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Bone and Mineral

A M Parfitt
No abstract text is available yet for this article.
December 1994: Bone and Mineral
A Ornoy, M Suissa, P Yaffe, B D Boyan, Z Schwartz
Sex steroid hormones are known to have gender-dependent effects on bone and cartilage in vivo and in vitro. To investigate whether this is a general property of steroids, or is specific to the sex steroid hormones, we examined whether the effects on bone of 1,25-(OH)2D3 and 24,25(OH)2D3, the two active metabolites of vitamin D, are also gender-dependent. One-month-old male and female rats were treated for 1 month with various doses of 1,25-(OH)2D3, 24,25-(OH)2D3, or a combination of both metabolites. The direct effects of both metabolites on the skeleton of the treated animals were similar in male and female rats...
December 1994: Bone and Mineral
K Suzuki, S Yamada
Ascites sarcoma 180 (S180A) is a transplantable tumor which causes hypercalcemia in tumor-bearing mice, and stimulates bone resorption without parathyroid hormone-like activity. In the present study, parathyroid hormone-related protein (PTHrP) mRNA could not be detected in total RNA from S180A cells. Bone-resorbing activity (BRA) derived from serum-free conditioned medium of S180A cells (S180A-CM) was coeluted with either transforming growth factor alpha (TGF alpha) activity (peak A, approximate M(r), 29 kDa) or lymphocyte-activating factor (LAF) activity (peak B, M(r), 20...
December 1994: Bone and Mineral
G P Lyritis, C Androulakis, B Magiasis, Z Charalambaki, N Tsakalakos
Eighty-eight postmenopausal women with at least one vertebral collapse were randomly assigned to two groups of 44 patients each. All patients were treated for a period of 12 months with 50 mg of nandrolone decanoate every 3 weeks or 1 microgram of 1-alpha-hydroxy-calciferol daily. Both groups received an identical placebo of the inactive drug. Pain intensity was significantly decreased in the nandrolone group and mobility was improved. Patients treated with vitamin D metabolite had also a beneficial but less obvious clinical result...
December 1994: Bone and Mineral
R Wildburger, N Zarkovic, G Egger, W Petek, K Zarkovic, H P Hofer
Healing of fractures of long bones or large joints is often accelerated in patients with severe traumatic brain injury (TBI). However, in these patients an early fracture healing is accompanied by hypertrophic callus formation or heterotopic ossifications which might even result in an ankylosis of the affected joints. It seems that enhanced osteogenesis in patients suffering from TBI could be caused by some humoral factors, since the sera of these patients strongly promote the growth of osteoblast cells in vitro...
December 1994: Bone and Mineral
G S Seo, M Shiraki, C Aoki, J T Chen, J Aoki, K Imose, Y Togawa, T Inoue
A modified and improved radiographic absorptiometry of the distal radius which enables on-site analysis, called computer assisted X-ray densitometry (CXD), was evaluated from the viewpoint of quality assessment. Its precision and the correlation with dual energy X-ray absorptiometry (DXA) was evaluated in 12 volunteers (mean age 44.7 years). The profile of CXD-measured radial bone mineral density (RBMD) from 142 subjects (75 premenopausal and 67 postmenopausal women, mean ages 44.9 and 50.6 years, respectively) were compared with previous data by other methodologies of bone mineral analysis...
December 1994: Bone and Mineral
M Amling, H J Grote, M Pösl, M Hahn, G Delling
It was the aim of this study to record quantitatively and qualitatively the distribution of the three-dimensional microarchitecture throughout the human spine in osteoporosis. Bone biopsies of the iliac crest and the complete spine of 26 autopsy cases without skeletal disease and 11 female patients with proven osteoporosis were removed. Grindings of all vertebrae by a technique which we developed allowed two- and three-dimensional measurements simultaneously. The analysis included an evaluation of trabecular bone volume, trabecular interconnection, and trabecular thickness, as well as a qualitative investigation of the structure of cancellous bone...
December 1994: Bone and Mineral
T J Hall, M Schaueblin
It is well established that osteoclasts use a vacuolar-type H(+)-ATPase (V-ATPase) for proton pumping during bone resorption and that specific V-ATPase inhibitors such as bafilomycin A1 abolish osteoclastic bone resorption in the bone slice assay. It has been reported that the V-ATPase in avian osteoclasts can be distinguished from the V-ATPase expressed in most other cells, by virtue of its inhibition by vanadate and nitrate ions. In order to determine whether the V-ATPase in mammalian osteoclasts can be similarly distinguished, we have investigated the effects of vanadate and nitrate on bone resorption by rat osteoclasts in the bone slice assay, in comparison with known V-ATPase inhibitors, bafilomycin A1 and WY 47766, that also inhibit the chicken osteoclast V-ATPase...
November 1994: Bone and Mineral
T Pitcher, J M Pettifor, R Buffenstein
The Damara mole-rat, Cryptomys damarensis, has no access to obvious dietary or endogenous sources of vitamin D. We tested the hypotheses that mineral metabolism in these animals is independent of vitamin D status but rather is affected by dietary calcium (Ca) content. Furthermore, we questioned whether bone and teeth assist in plasma mineral homeostasis. Mole-rats increased Ca intake when dietary Ca content increased; however, mode of gastrointestinal uptake, vitamin D metabolite and plasma Ca concentrations were not altered...
November 1994: Bone and Mineral
C Igarashi, T Maruyama, I Ezawa, I Takei, T Saruta
A long-term investigation of bone mineral metabolism in a newly developed strain, the WBN/Kob rat, which spontaneously develops diabetes, possibly due in part to hemosiderin deposition, was conducted. WBN/Kob rats used in this study developed diabetes after 9 months of age. Bone mass peaked at 6 months or 8 months of age, and femoral breaking strength was maximal at 8 months of age, declining rapidly after the development of diabetes. In contrast, both the bone mass and the mechanical strength increased up to 14 months of age in controls...
November 1994: Bone and Mineral
V L Schultz, S C Garner, J R Lavigne, S U Toverud
A new homologous 2-site assay for rat parathyroid hormone (IRMA), developed by Immutopics, Inc., has been evaluated and compared with a bone cell cAMP bioassay. Circulating PTH for adult rats assayed with this IRMA are in the range 10-15 pg/ml, and of the same order of magnitude as published values for biologically active PTH. The standard curve for the IRMA was linear over the range 3.4-240 pg/ml of rPTH 1-34, and serum samples diluted in parallel with the standard curve. The within-assay and between-assay coefficients of variation ranged from 5...
November 1994: Bone and Mineral
J Pearson, P Ruegsegger, J Dequeker, M Henley, J Bright, J Reeve, W Kalender, D Felsenberg, A M Laval-Jeantet, J E Adams
A semi-anthropomorphic 'distal radius like' phantom, developed by Kalender and Ruegsegger for use in peripheral bone densitometry using single photon (DPA) dual X-ray (DXA) and quantitative computed tomography (QCT) machines, has been studied with a view to cross-calibrating different types and brands of densitometers in current use. In the context of an EU 'Concerted Action' (second Framework Programme) the phantom was repeatedly measured on six SPA machines, three DXA machines and nine QCT machines (545 measurements)...
November 1994: Bone and Mineral
E Bornefalk, S Ljunghall, A G Johansson, K Nilsson, O Ljunggren
Interleukin-1 (IL-1) is a potent stimulator of bone resorption. Induction of osteoclastic bone resorption by various endocrine or paracrine factors is mediated via the osteoblasts. We have therefore investigated the effects of IL-1 beta on cell signalling in isolated human osteoblasts. Special interest was focused on prostaglandin synthesis, since indomethacin, an inhibitor of prostaglandin synthesis, partly inhibits IL-1-induced bone resorption. IL-1 beta, at and above 0.3 pM, dose dependently stimulated PGE2 formation in isolated human osteoblasts, with half maximal stimulation, EC50, at 3 pM...
November 1994: Bone and Mineral
Y Kadoya, N al-Saffar, A Kobayashi, P A Revell
The expression of some candidate osteoclast markers, tartrate-resistant acid phosphatase (TRAP), macrophage associated antigens (M phi Ag), and vitronectin receptor (VNR) on foreign body giant cells (FBGCs) was investigated in peri-implant tissues of loosened total joint arthroplasties. Osteoclasts showed distinct staining characteristics. They were strongly TRAP-positive at tartrate concentrations of 50-200 mM and expressed VNR and a restricted range of M phi Ag. In contrast, FBGCs were shown to be significantly heterogeneous...
November 1994: Bone and Mineral
K Nohtomi, K Sato, K Shizume, K Yamazaki, H Demura, K Hosoda, Y Murata, H Seo
Interleukin-4 (IL-4) potently inhibits bone resorption by preventing the differentiation of osteoclast precursors to osteoclasts. To elucidate the role of IL-4 in bone formation, we studied the effects of human IL-4 on human osteoblast-like cells obtained from trabecular bone, which showed increased osteocalcin production in response to 1,25-(OH)2D3 in more than 10 passages. IL-4 stimulated the proliferation of osteoblast-like cells in a concentration-dependent manner, showing the minimal and maximal stimulatory effects at 10 pg/ml and 100-1000 pg/ml, respectively...
October 1994: Bone and Mineral
A Sabokbar, P J Millett, B Myer, N Rushton
Alkaline phosphatase (ALP) is the most widely recognized biochemical marker for osteoblast activity. Although its precise function is poorly understood, it is believed to play a role in skeletal mineralization. The aim of this study was to develop an assay suitable for measuring the activity of this enzyme in microtiter plate format. Using the well-characterized osteoblast-like cell line Saos-2, this paper describes an optimized biochemical assay suitable for measuring ALP activity in tissue culture samples...
October 1994: Bone and Mineral
S D Vasikaran, D P O'Doherty, E V McCloskey, B Gertz, S Kahn, J A Kanis
We report the effects of alendronate on phosphate homeostasis in two patients. In a woman with postmenopausal osteoporosis, the infusion of alendronate (7.5 mg intravenously daily for 4 consecutive days) was not associated with secondary hyperparathyroidism despite a reduction in serum calcium. This was associated with a rise in serum phosphate and TmP/GFR. This response contrasted with those observed in 14 other patients with osteoporosis, in whom PTH rose significantly following the infusion of alendronate in association with a significant fall in serum phosphate and TmP/GFR...
October 1994: Bone and Mineral
C A Walsh, M A Birch, W D Fraser, J Robinson, R Lawton, J Dorgan, L Klenerman, J A Gallagher
Parathyroid hormone-related protein (PTHrP), a mediator of hypercalcemia of malignancy, has been detected in many tumours and in some normal foetal and adult tissues. PTHrP has potent effects on bone turnover in vivo and in vitro. In this study we cultured cells derived from explants of bone obtained from 40 subjects (age range 2-88 years). Immunoreactive PTHrP (iPTHrP) was detected by immunoradiometric assay (IRMA) in conditioned medium from 25 of 40 cultures of bone-derived cells. PTHrP mRNA was detected in bone-derived cells by reverse transcriptase-linked polymerase chain reaction (RT-PCR)...
October 1994: Bone and Mineral
H Kröger, E Alhava, R Honkanen, M Tuppurainen, S Saarikoski
Bone mineral density (BMD) of the spine and femoral neck was measured in a random stratified sample of 3222 perimenopausal women aged 47-59 years. A total of 969 women had used fluoridated drinking water (1.0-1.2 mg/l) for over 10 years. These women were compared with 2253 women with low levels of fluoride in drinking water (< 0.3 mg/l). BMD of the spine was significantly higher in the fluoride group than in the non-fluoride group (1.138 +/- 0.165 vs. 1.123 +/- 0.156 g/cm2, P = 0.026). Femoral neck BMDs did not differ between the groups...
October 1994: Bone and Mineral
J Martínez, J M Olmos, A L de Francisco, J A Amado, J A Riancho, J González-Macías
A decreased number of calcitriol (1,25(OH)2D3) receptors has been observed in parathyroid glands of uremic animals. In humans, studies carried out in surgically removed parathyroid glands have shown that calcitriol binding is higher in primary than in secondary hyperparathyroidism. Since specific receptors for calcitriol have been described in peripheral blood mononuclear cells (PBMC), we have investigated the specific uptake of 3H-labelled 1,25(OH)2D3 in PBMC of 12 women with primary hyperparathyroidism (PHP), 8 women with hyperparathyroidism secondary to chronic renal failure (SH), 9 women with renal transplant (RT), and 23 healthy women...
October 1994: Bone and Mineral
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