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Our aim in this cross-sectional study was to measure forearm bone mineral density (BMD) in postmenopausal women with a previous history of hyperthyroidism, comparing those remaining euthyroid after treatment and those requiring thyroxine therapy with the local control population.Our 106 subjects were divided into four groups: treated with radioiodine, remaining euthyroid (RU, n=15); treated with radioiodine...
Osteoporosis is a common complication after cardiac transplantation, but the mechanism of bone loss is unclear. We studied 50 men 1 to 47 months after cardiac transplantation (ages 18 to 64 years) who received prednisolone and cyclosporin A to prevent rejection, and 50 men as controls (ages 20 to 70 years). We measured bone resorption using urinary cross-linked N-terminal telopeptide of type I collagen...
The growth and differentiation of monocytic cells, which express VDR, may be modulated by local inflammatory mediators such as PGs. We have studied the effects of PGE 2 on an adherent variant (Ad-HL60) of the promyelomonocytic HL60 cell line. Treatment with 1 μM PGE 2 resulted in;These results suggest that PGE 2 may play a role in the differentiation of monocytes. This process...
We have developed an experimental model whereby a single episode of mechanical stimulation induces bone formation in caudal vertebrae of rats. We have found that osteocytic expression of IGF-1 precedes matrix gene expression by cells on bone surfaces. We have now assessed expression of other genes that might be involved in mechanical responsiveness. The 6th (C6) (non-loaded control) and 8th (C8)...
Studies in animals suggest that different sites in the skeleton experience different levels of mechanical loading. We investigated human bone strain by bonding two planar rosette gauges to the parietal bone of the skull and a third gauge to the midshaft of the tibia of a normal (!) volunteer during walking, squatting, lifting weights, and jumping. To load the skull, the subject chewed a variety...
Despite being an abundant cell type in bone the function of osteocytes remains unclear. The general consensus is that they play a mechanosensory role in bone and modulate the formation and activity of osteoblasts and osteoclasts although the signals responsible for this control are unknown. The necrotic death of osteocytes has been associated with conditions of low bone turnover such as in old age...
Earlier we found reconstructed wall width (rW.Wi) by Steiniche's method (Bone 1992, 13:147) in bone biopsies from 12 patients with renal osteodystrophy smaller, activation frequency (Ac.F) higher, appositional rate equal but the formative period (FP) protracted, compared to age- and sex-matched controls.We aimed to test whether these inconsistent results were due to overestimation of (active) osteoid...
To determine whether androgens are involved in the regulation of bone formation in females, we studied the effect of androgen replacement on histomorphometric indices at the proximal tibial metaphysis of 13-week-old ovariectomised rats. Animals were also given the potent resorption-inhibitor APD to prevent the increase in bone resorption which occurs after ovariectomy from indirectly influencing...
Recent studies have shown that biochemical markers of bone formation can be measured in equine serum. However, markers of bone resorption can only be measured reliably in urine and it is not practical to collect this regularly from horses. The aim of this study was to develop a method for pyridinium crosslinks in equine serum. Serum from 50 thoroughbreds (age range 1 week to 10 years) was purified...
Background. Abnormal mechanical loading has been implicated in the initiation and progression of diseases such as osteoarthritis. Our previous work has shown that articular chondrocytes in explant culture respond rapidly (+ 4hr) to mechanical load by modifying production of matrix components. The mechanisms underlying this response are unclear. In order to identify response genes which are activated...
There have been many cross-sectional studies of bone density in women of different ages, but there is a shortage of longitudinal data on rates of change. We have studied a large group of female volunteers (Shropshire Osteoporosis Study) over 4 years and present the preliminary profiles of rates of change for those aged 35-80 years at the mid point of the 4 year interval. There were 254 of these,...
Parathyroid hormone is secreted from the parathyroid glands and acts on target receptors in osteoblastic cells to regulate bone remodelling in a classical endocrine manner. It has recently been demonstrated that parathyroid hormone-related peptide (PTHrP) can be synthesised in bone, and since PTHrP can activate the same receptor as PTH (PTH/PTHrP receptor) with equivalent potency, autocrine or paracrine...
Acoustic velocity measurements are used to estimate tissue-level bone strength after fluoride therapy for osteoporosis. However, acoustic measurements provide information about elasticity, not strength, and bone elasticity does not necessarily correlate with bone strength at a tissue level. The current study was undertaken to evaluate the effects of fluoride treatment on tissue-level acoustic velocities,...
Oestrogen status is considered to influence bone metabolism and may have direct effects on both bone tissue and clearance of metabolites such as the collagen propeptides which are cleared by the liver.We have investigated the effects of menopause and therapy for bone loss on the circulating collagen type I propeptide levels PINP, PICP and PIIINP (by RIA (μg/L), Orion, Finland) in 19 screened healthy...
Increased understanding of bone cell differentiation will prove important in the treatment of metabolic bone disease. Key factors in the differentiation of pluripotential stromal stem cells in human bone marrow are glucocorticoids and oestrogens. In addition, cellular differentiation is regulated by a variety of mechanisms, including agents that modulate the methylation of DNA. In the present study...
Osteocalcin (OC) is a bone matrix protein, synthesized by osteoblasts, which contains three residues of gammacarboxy-glutamic acid (GLA). A fraction of circulating OC, which is not fully carboxylated and does not bind to hydroxyapatite, is called undercarboxylated OC (ucOC). In elderly institutionalized women, we have shown an increase of circulating ucOC level which may result not only from vitamin...
The possibility of consistent systematic variability in the age matched Z scores among individual lumbar vertebrae when measuring anterior posterior spinal bone density on the Lunar DPX aplha was investigated in 200 consecutive patients referred for screening for osteoporosis. Patients were 8 male, 192 female, of average 57 years (range 33-89) and without known vertebral fractures. Patients were...
Premature osteoporosis is a recognised complication of anorexia nervosa, but the mechanisms for bone loss are unclear. To examine systemic changes in bone turnover, we measured novel biochemical bone markers in 36 anorexia nervosa patients (17-46 years) to complement conventional tests. Anorexia nervosa was diagnosed by standard criteria, 19 were outpatients and 17 in-patients, with average duration...
Hepatitis C has recently been recognized as a secondary cause of osteosclerosis; a further example, the first outside of North America, is described. A 37-year-old man with a history of intravenous drug use and known to be hepatitis C antibody positive presented with bone pain. Radiographs and magnetic resonance imaging demonstrated an increase in cortical and trabecular bone that on biopsy was of...
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