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We report the predictive value for hip fracture of a new marker of bone resorption, serum C-telopeptide of type I collagen (CTX), measured on a new automated analyzer, Elecsys. Baseline urinary and serum samples from 212 patients who subsequently had a hip fracture and from 642 controls were analyzed in a nested case control study within the EPIDOS prospective cohort. Each fracture patient was matched...
Because of the low and variable bioavailability of bisphosphonates and the huge effect of food on their gastrointestinal absorption, it is of utmost importance to know the optimal timing of drug intake in relation to food intake. We investigated the effect of time on the bioavailability of clodronate when the drug was administered 2, 1, or 0.5 h before breakfast, with breakfast, or 2 h after breakfast...
Fatigue fracture of the cuboidal bones of the foot, especially the navicular tarsal bone, is common in athletes and dancers. The racing greyhound is a naturally occurring animal model of this injury because both microcracking and complete fracture occur in the right central (navicular) tarsal bone (CTB). The right limb is on the outside when racing in a counter-clockwise direction on circular tracks,...
Mechanical loading of bone stimulates resident bone cells to produce prostacyclin (PGI 2 ) and prostaglandin (PG)E 2 by a mechanism that can be differentially regulated by ion channel blockers. We have investigated differences in the loading-related PG production mechanisms in rat ulnae explants loaded ex vivo. Loading and aluminium fluoride (AlF 3 , a nonselective activator...
While osteoporosis is characterized by a low bone mass there is a well-recognized overlap in bone mineral density (BMD) measurements between groups of subjects with and without vertebral fracture. To investigate whether differences in trabecular architecture may contribute to the presence or absence of fractures independent of the bone mass, fracture and nonfracture groups matched for age, gender,...
A gap junction-deficient cell line was utilized to test whether intercellular coupling plays a significant role in modulating the influence of biophysical stimuli such as extracellular electrical currents. ROS 17/2.8 cells, an osteosarcoma cell line, along with a control transfected cell line and a connexin 43-gap junction-deficient cell line, were exposed to a time-changing magnetic flux (30 Hz,...
It has been suggested that, in hip fracture, the cortex on the inferoanterior (IA) to superoposterior (SP) axis is thinned and shows increased porosity. This is dependent on the presence of giant canals (i.e., diameter >385 μm), which are related to clusters of remodeling osteons. To investigate further the relationship between remodeling and bone loss, osteonal diameter (On.Dm), wall thickness...
This cross-sectional study is based on images from the lower leg as assessed by peripheral quantitative computer tomography (pQCT). Measurements were performed in 39 female and 38 male control subjects and 15 female professional volleyball players, all between 18 and 30 years of age. The images were obtained at shank levels of 4%, 14%, 33%, and 66% from the distal end. Bone and muscle cross-sectional...
Diabetes is associated with low bone formation. In this study we investigate the effect of additional or reduced mechanical loading on indices of bone formation and resorption, bone mass, and biomechanical properties in spontaneously diabetic BB rats. Female diabetic (mean age 13 weeks) and age-matched control rats were each allocated to three experimental groups: no-intervention; supervised running...
Because the extracellular matrices of dentin and bone are composed mainly of type I collagen, their characteristics are determined by the nature of noncollagenous proteins (NCPs). Among these NCPs, some proteoglycans (PGs) belong to the small leucine-rich proteoglycans (SLRPs). Recently, osteoadherin (OSAD) has been described as a new member of this family, that is expressed by mature bovine osteoblasts...
The purpose of this study was to determine the effects of basic fibroblast growth factor (bFGF) on cortical bone in ovariectomized (ovx) rats. Female Sprague-Dawley rats were subjected to sham surgery or ovariectomy at 3 months of age and maintained untreated for 2 months after surgery. Polyurethane catheters were then inserted in the jugular veins of all rats for daily intravenous treatments with...
Bone marrow stromal cells can undergo adipogenesis or osteoblastogenesis in vitro and in vivo. This review explores the stromal cell's differentiation plasticity in the context of osteoporosis and other metabolic bone disorders. Attention is focused on the apparent reciprocal relationship that is postulated to exist between the adipocyte and osteoblast phenotypes. The signal transduction pathways...
It has been suggested that quantitative ultrasound measurements (QUS), which reflect mainly bone density, could be influenced by bone micro-architecture. The aim of the study was to assess whether the relationship of QUS to dual X-ray absorptiometry (DXA) would reflect abnormalities of bone structure observed in renal osteodystrophy. QUS and bone mineral density of the calcaneus (BMDc) were measured...
We recently developed a simple and inexpensive method that complements established bone histomorphometry procedures by enabling the two-dimensional imaging of cancellous bone to be viewed within its three-dimensional context with the marrow tissue in place and without detriment to the material for other histological purposes. The method, based on the preparation and superficial staining of slices...
The involvement of the estrogen receptor in the early responses of bone cells to mechanical strain was investigated by subjecting subconfluent monolayer cultures of ROS.SMER #14 cells (ROS 17/2.8 cells stably transfected with additional ERα) to 17β-estradiol or a single short period of dynamic mechanical strain (600 cycles, 1 Hz). The basal proliferation rate of ROS.SMER #14 cells was similar to ROS...
Parathyroid hormone (PTH) increases trabecular but may decrease cortical bone mass during treatment of postmenopausal osteoporosis. In a 2-year trial, PTH, with or without sequential calcitonin (CT), was given to 29 osteoporotic women (mean age 67 +/- 7 years), in 3-month cycles [28 days hPTH(1-34), 50 μg/day, +/-42 days CT, 75 units/day, 20 days ''free'']. Over 2 years, lumbar spine bone mineral...
Osteoblast differentiation and function can be studied in situ in the metaphysis of growing long bones. Proliferation and apoptosis dominate in the primary spongiosa subjacent to the growth plate, and differentiation and function dominate in the proximal metaphysis. Apoptosis of osteocytes dominates at the termination of the trabeculae in diaphyseal marrow. As parathyroid hormone regulates all phases...
This study was performed to evaluate supra- and sublesional bone mineral density (BMD) in spinal cord-injured (SCI) patients after 1 year postinjury, and to correlate the BMD to the neurological level; to correlate the sublesional demineralization to functional parameters (duration postinjury, duration of the initial bedrest); and to assess the role of classic methods of prevention such as walking...
Autologous marrow stromal cells have been proposed as an adjuvant in the treatment of bone defects and diseases. This will require the development of culture conditions that permit their rapid expansion ex vivo while retaining their potential for further differentiation. Fibroblast growth factor (FGF)-2 has been proposed as a candidate for the ex vivo expansion of cells with enhanced osteogenic potential,...
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