Bisphosphonate resistance in Paget's disease of bone.
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OBJECTIVE: To determine whether resistance to one bisphosphonate predicts resistance to another bisphosphonate. METHODS: One hundred patients with Paget's disease were treated with intravenous (IV) pamidronate. The initial dose was 120 mg, followed by further doses of 240 mg, until either biochemical remission was achieved or a total dose of 1 gm was given. Biochemical remission was defined as an alkaline phosphatase level within the reference range. Patients whose disease failed to respond to pamidronate were then treated with alendronate for 6 months. Patients whose disease failed to respond to alendronate were given either tiludronate for 3 months, or clodronate for 6 months. RESULTS: Sixteen of the 100 patients treated with pamidronate failed to achieve a biochemical response despite a cumulative dose of 1 gm. Of the 16 nonresponders, 1 died of an unrelated cause, and the remaining 15 patients were treated with alendronate. In 2 of these patients, the treatment was changed to another bisphosphonate because of gastrointestinal intolerance to alendronate. Of the remaining 13 patients, 9 (69%) achieved full biochemical remission. In 4 other patients, both pamidronate and alendronate therapy were unsuccessful (1 patient responded to tiludronate, tiludronate therapy was unsuccessful in 1, clodronate was unsuccessful in 1, and 1 patient elected to receive no further treatment). Of the 2 patients who could not receive alendronate because of gastrointestinal intolerance, 1 achieved normalization with tiludronate, and a repeat course of pamidronate was unsuccessful in the other. In total, 73% of patients in whom initial treatment with IV pamidronate was unsuccessful responded to a change in bisphosphonate treatment. CONCLUSION: Failure to achieve biochemical normalization is likely to be specific to the individual drug rather than indicative of bisphosphonate class resistance. (+info)
Effect of bisphosphonate treatment in patients with Paget's disease of the skull.
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OBJECTIVES: Hearing loss has long been known to be a complication of Paget's disease of bone. The aim of this study was to investigate Paget's disease of the temporal bone with special attention to hearing loss. METHODS: Twenty-five patients with skull involvement were treated with either pamidronate or tiludronate. Imaging included radiography, quantitative bone scintigraphy (QBS), single photon emission computed tomography (SPECT) and high-resolution computed tomographic (HRCT) scanning. Audiometric assessment was also performed. RESULTS: Twenty-three of the 25 patients with skull involvement suffered from hearing loss. Bisphosphonate treatment resulted in a decreased serum total alkaline phosphatase (serum tAP) level and QBS ratio, and also seemed to improve the complaints of the patients. HRCT demonstrated involvement of the middle ear ossicles (n = 7), involvement of the petrous pyramids (n = 14), demineralization of the otic capsule (n = 10), porosis pericochlearis (n = 8), narrowing of the external auditory meatus (n = 12), mastoid process thickening (n = 5) and stapedial footplate thickening (n = 4). The audiometric examination did not show any significant changes 1 yr after bisphosphonate treatment. CONCLUSIONS: HRCT imaging is a well suited tool for demonstrating the complication of Paget's disease. QBS and measurement of serum tAP level may also be regarded as useful techniques for monitoring treatment. However, hearing may remain impaired in spite of the improved scintigraphy and laboratory parameters, therefore, audiometric assessment is also important in pagetic patients with skull involvement. (+info)
Lumbar spinal stenosis in the elderly: an overview.
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Lumbar spinal stenosis is a common condition in elderly patients and also one of the most common reasons to perform spinal surgery at an advanced age. Disc degeneration, facet degeneration and hypertrophy, and ligamentum flavum hypertrophy and calcification usually participate in the genesis of a stenotic condition in the elderly. These changes can lead to symptoms by themselves or decompensate a preexisting narrow canal. Although some lesions are more central or more lateral, this classic dichotomy is less present in the elderly patient, in whom the degenerative process usually encroaches both central and lateral pathways. Some less common causes of lumbar spinal stenosis are found in the aging subject, such as Paget's disease. However, it must be stressed that so-called stenotic images (sometimes severe) are present on imaging studies in a great number of symptom-free individuals, and that the relationship between degenerative lesions, importance of abnormal images, and complaints is still unclear. Lumbar stenosis is a very common reason for decompressive surgery and/or fusion. Various conditions can lead to a narrowing of the neural pathways and differential diagnosis with vascular troubles, also common in the elderly, can be challenging. The investigation of stenotic symptoms should be extremely careful and thorough and include a choice of technical examinations including vascular investigations. This is of utmost importance, especially if a surgical sanction is considered to avoid disappointing results. (+info)
Two-site assays of bone gla protein (osteocalcin) demonstrate immunochemical heterogeneity of the intact molecule.
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We developed a panel of monoclonal antibodies to human bone gla protein (BGP; osteocalcin) peptides that span the linear sequence of the molecule, specifically BGP 1-12 (N-terminal), BGP 15-30 (midregion), and BGP 38-49 (C-terminal). These antibodies were evaluated in various combinations of two-site formats in studies of serum BGP concentrations. For clinical studies, we selected from a panel of antibodies the two most sensitive antibody pairs for the intact molecule (N-C); we also used a polyclonal RIA based on BGP-C. For the two-site format, we used two N-terminal antibodies, 029 and 052, adsorbed to polystyrene beads, and radioiodinated a C-terminal antibody, 663. The standard for each of the assays was purified human BGP. The following BGP serum concentrations (microgram/L, mean +/- SE) were measured with the various assays: by the 029-663 assay, results for normal subjects were 7 +/- 3, for patients with renal failure 25 +/- 8, and for patients with Paget disease 12 +/-4; by the 052-663 assay, the respective results were 22 +/- 4, 44 +/- 12, and 31 +/- 7; by the polyclonal assay, the results were 3 +/- 0.2, 13 +/- 2, and 5 +/- 1. The two intact (N-C) assays were significantly (P < 0.01) correlated (r = 0.94), but their serum values differed by more than twofold in terms of the same BGP standard. The polyclonal assay significantly correlated with each of the intact assays (r = 0.83, 0.77), but it, too, gave different serum values for BGP. These studies demonstrate the immunochemical heterogeneity of circulating BGP, heterogeneity that is manifest even in immunoassays specific for the same region of the molecule. (+info)
Bone-resorption markers galactosyl hydroxylysine, pyridinium crosslinks, and hydroxyproline compared.
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We compared the clinical performances of four bone-resorption (BR) assays (hydroxyproline, HYP; galactosyl hydroxylysine, GHYL; deoxypyridinoline, DPD; and pyridinoline, PYD) in subjects with different BR rates: normal (adult men and premenopausal women), mildly increased (postmenopausal osteoporotic women), high (Paget disease patients), and very high (children). The discrimination power (Z score) and the accuracy (estimated by receiver-operating characteristic analysis) for GHYL, DPD, and PYD were compared with those for HYP. Discrimination power and accuracy were similar for high- and very-high-BR groups for all four assays. However in the mildly increased-BR group, DPD, GHYL, and PYD showed a higher discrimination power and accuracy than did HYP. The clinical performances of HYP, DPD, GHYL, and PYD are comparable for large changes in BR. For modest changes, DPD, GHYL, and PYD are more accurate and have a higher discrimination power than does HYP. (+info)
SOME ASPECTS OF CALCIUM METABOLISM IN MALIGNANT DISEASE OF BONE.
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The rate of calcification of new bone (accretion rate) was measured by a radioisotope technique in 20 patients with carcinoma of the breast, 14 patients with multiple myelomatosis, five patients with Paget's disease of bone, and in six patients with solitary, non-osseous tumours. The rate of bone destruction was assessed in these patients by the measurement of the rate of urinary calcium excretion. In the patients with carcinoma of the breast and bone metastases there was a marked increase both in the accretion rate and in the urinary calcium excretion suggesting an osteoblastic response to bone destruction. An osteoblastic response was also present in the patients with multiple myelomatosis but was not correlated with the urinary calcium excretion. In patients with Paget's disease of bone, high values of accretion rate were found indicating very active new bone formation. (+info)
Paget's disease; changes occurring following treatment with newer hormonal agents.
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From experience in six cases the anabolic steroid hormones, especially long-acting testosterone and estrogen preparations, are the treatment of choice in Paget's disease, as in postmenopausal osteoporosis. Details of the management of three patients over a period of four years are presented. Roughly 4 per cent of the population, mostly persons over 40, show some evidence of Paget's disease. Only a small number of them, however, have severe manifestations requiring treatment, such as pain, howing or fracture of the bones, pressure on nerves or heart failure. In rare cases malignant changes occur in the involved bone. Since the cause of Paget's disease is not known, treatment in the past has been largely empirical. Reifenstein and Albright had advocated the therapeutic use of calcium, vitamin D and ascorbic acid, and, in postmenopausal women, administration of estrogens; but with fractures or immobilization, intake of calcium-containing foods, such as milk, must be restricted to avoid dangerous piling up of calcium and kidney stones, and fluids must be forced. In recent years anabolic steroid hormones, principally oral androgens and estrogens, have been employed by Gordan and others to promote bone repair, lessen bone pain and decrease urinary excretion of calcium. While these hormones probably do not arrest the disease, they seem to stabilize it and bring relief of symptoms. More recently, Albright and Henneman demonstrated that very large doses of corticotropin (ACTH) or cortisone resulted in immediate cessation of bone pain, decrease in urinary excretion of calcium and histologic evidence of regression of the disease process. The large doses required, however, also produce dangerous side effects, such as psychosis and osteoporosis, indicating that such treatment probably should not be continued over long periods. (+info)
Principles of management of osteometabolic disorders affecting the aging spine.
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Osteoporosis is the most common contributing factor of spinal fractures, which characteristically are not generally known to produce spinal cord compression symptoms. Recently, an increasing number of medical reports have implicated osteoporotic fractures as a cause of serious neurological deficit and painful disabling spinal deformities. This has been corroborated by the present authors as well. These complications are only amenable to surgical management, requiring instrumentation. Instrumenting an osteoporotic spine, although a challenging task, can be accomplished if certain guidelines for surgical techniques are respected. Neurological deficits respond equally well to an anterior or posterior decompression, provided this is coupled with multisegmental fixation of the construct. With the steady increase in the elderly population, it is anticipated that the spine surgeon will face serious complications of osteoporotic spines more frequently. With regard to surgery, however, excellent correction of deformities can be achieved, by combining anterior and posterior approaches. Paget's disease of bone (PD) is a non-hormonal osteometabolic disorder and the spine is the second most commonly affected site. About one-third of patients with spinal involvement exhibit symptoms of clinical stenosis. In only 12-24% of patients with PD of the spine is back pain attributed solely to PD, while in the majority of patients, back pain is either arthritic in nature or a combination of a pagetic process and coexisting arthritis. In this context, one must be certain before attributing low back pain to PD exclusively, and antipagetic medical treatment alone may be ineffective. Neural element dysfunction may be attributed to compressive myelopathy by pagetic bone overgrowth, pagetic intraspinal soft tissue overgrowth, ossification of epidural fat, platybasia, spontaneous bleeding, sarcomatous degeneration and vertebral fracture or subluxation. Neural dysfunction can also result from spinal ischemia when blood is diverted by the so-called "arterial steal syndrome". Because the effectiveness of pharmacologic treatment for pagetic spinal stenosis has been clearly demonstrated, surgical decompression should only be instituted after failure of antipagetic medical treatment. Surgery is indicated as a primary treatment when neural compression is secondary to pathologic fractures, dislocations, spontaneous epidural hematoma, syringomyelia, platybasia, or sarcomatous transformation. Five classes of drugs are available for the treatment of PD. Bisphosphonates are the most popular antipagetic drug and several forms have been investigated. (+info)