bluuebunny/crossref_metadata_2025_split huggingface dataset:
Journal of Bone and Mineral Research
Authors: Ferretti Jose L. , Spiaggi Eduardo P. , Capozza Ricardo , Cointry Gustavo , Zanchetta Jose R. 
Published: February 2010

Abstract
In femora from rats or mice, the area and moment of inertia (but not the wall-lumen ratio) of a diaphyseal section correlated with biomass and were determinants of the strength and stiffness of the integrated bone. In otter metacarpals, however, the geometric variable typically associated with body weight and mechanical ability of the integrated bone was the wall-lumen ratio (not the sectional moment of inertia). These differences may be associated with the meaningfulness of body density for natural selection in diving species like otters. A negative relationship between wall-lumen ratio and material modulus of elasticity in bones from the three species pointed out the impossibility of increasing diaphyseal thickness and stiffness at the same time. The results are compatible with the hypothesis that ecologic habits are selectively more important than phylogenetic relationships between species for the determination of bone mechanical properties in the upper vertebrates.
Journal of Bone and Mineral Research
Authors: Vico L. , Alexandre C. 
Published: February 2010

Abstract
Our knowledge of the adaptation of human bone microgravity remains poor despite long-term Russian spaceflights and the recent use of accurate techniques for bone mass measurements. The extent of bone deficits in the adaptation of the whole skeleton is not clear. At the tissue level, bone resorption and formation activities have been studied only in bones from rats after spaceflights lasting a few days to 3 weeks. In these animals, architectural features consistent with osteoporosis have been found in the proximal tibia. In pregnant animals the osteoclast population is increased at other skeletal sites. In areas of weight-bearing bones that are not protected by muscular insertions, bone resorption is not markedly altered after 7 days of spaceflight and bone formation is reduced. In areas of weight-bearing bones with muscular insertions and in non-weight-bearing bones, similar changes in bone cell activity are delayed. The severity of the response seems to vary with the location of the bone in the skeleton and its initial level of bone turnover. After 12.5 days the acute bone changes are less and no additional changes are observed after 21 days in space. We conclude that generalized bone deficits do not appear to be a consequence of microgravity but occur in localized areas according to the level of modeling and remodeling and of the support function of each bone at 1 g.
Changes in axial bone density with age: A twin study
Authors: Kelly Paul J. , Nguyen Tuan , Hopper John , Pocock Nicholas , Sambrook Philip , Eisman John 
Published: February 2010

Abstract
Bone mineral density in adult life, which is an important determinant of fracture risk, is determined by peak adult bone density, achieved in early adulthood and subsequent rates of change during adult life. Cross-sectional twin and family studies indicate that the majority of population variation in bone density may be explained by genetic factors. Although there is evidence for a genetic effect on peak bone mass, it is unknown whether there is a genetic effect on rates of changes in bone density with age. Changes in lumbar spine and femoral neck bone density determined by dual-photon absorptiometry (Lunar DP3) were examined in a cohort of monozygotic (MZ, n = 21, 3 male and 18 female pairs, median age, range, 46; 24–75 years) and dizygotic twins (DZ, n = 19; 43, 25–65 years). The median follow-up was 3 years (range 1.1–5.5 years), with each subject having at least two and up to four bone density assessments. In these twins, genetic factors determine variation in rates of change (% change/year) in lumbar spine bone density, rMZ = 0.93 and rDZ = 0.51, p &lt; 0.02 (one tailed), and Ward's triangle, rMZ = 0–60. rDZ = 0.11, p &lt; 0.05 (one tailed). Model-fitting analysis was also consistent with a genetic effect on rates of change in bone density at the trochanteric site, although such an effect was not shown at the femoral neck. These data demonstrate, for the first time, the possible existence of genetic determinants of rates of change in bone mineral density in adults.
Fluoride-stimulated [3H] thymidine uptake in a human osteoblastic osteosarcoma cell line is dependent on transforming growth factor β
Authors: Reed Berenice Y. , Zerwekh Joseph E. , Antich Peter P. , Pak Charles Y.C. 
Published: February 2010

Abstract
Controversy exists regarding the effect of fluoride on human osteoblast proliferation. To learn more of the cellular action of fluoride, we chose the clonal osteoblast cell line HOS TE85 as a model system. In these phenotypically osteoblast-like cells, sodium fluoride stimulated [3H]thymidine incorporation in a dose-dependent manner over the concentration range 1 × 10−5-2 × 10−4 M. The fluoride-induced stimulation of [3H]thymidine uptake was dependent on cell density, being optimal at subconfluent cell numbers. Stimulation of [3H]thymidine uptake was inhibited by anti-transforming growth factor β but not by antibody to insulin-like growth factor I or β2-microglobulin. Transforming growth factor β was shown to be a biphasic stimulator of [3H]thymidine uptake in HOS TE85, with maximal stimulation occurring at 0.5 nM transforming growth factor β. In the presence of fluoride the cells were more sensitive to stimulation by this growth factor, with maximum effect occurring at 0.1 nM. Fluoride did not increase mRNA for transforming growth factor β following either 8 or 24 h of exposure. We conclude that fluoride activates osteoblast proliferation by modulating the cellular sensitivity to transforming growth factor β, a known stimulator of bone growth.
Identification of a competitive binding component in vitamin D-resistant new world primate cells with a low affinity but high capacity for 1,25-dihydroxyvitamin D3
Authors: Gacad Mercedes A. , Adams John S. 
Published: February 2010

Abstract
Monkeys in a number of different New World primate genera express a form of compensated target organ resistance to steroid hormones, including 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. Characterization of these phenotypes has previously relied upon the study of the 1,25-(OH)2D3-receptor (VDR) interaction in cultured dermal fibroblasts from affected primates. In this report, we show that three of these prototypic phenotypes can be faithfully reproduced in previously established cultured cell lines: B95–8, EBV-transformed B lymphoblasts from the marmoset (Callithrix jacchus), a New World primate with recognized vitamin D resistance; OMK, renal tubular epithelial cells from the owl monkey (Aotus trivergatus), a New World primate with an Old World primate-like VDR phenotype; and MLA144, transformed B lymphoblasts from a gibbon (Hylobates), an Old World primate that expresses the wild-type VDR phenotype. The rank order of specific nuclear uptake and binding of [3H]1,25-(OH)2D3 to the VDR was OMK ≥ ML A144 » B95–8. Despite a 7- to 9-fold difference in cellular VDR content according to ligand binding analyses, there was no discernible difference in the internalization constant Kin for specific cellular uptake of [3H]1,25-(OH)2D3 (0.12–0.26 nM) or in the quantity of VDR detected by immunoblot analysis. We now speculate that the discrepancy in VDR quantitation by binding and immunoblot analysis in the B95–8 New World primate cell line results from the presence of an intracellular, vitamin D metabolite binding moiety in this cell line that competes with the VDR for metabolite binding. Extracts of B95–8 cells, but not wild-type MLA144 cells, exhibited a binding component that had a relatively low affinity (∼ 50 nM) but high capacity for 1,25-(OH)2D3 compared to the VDR. When mixed with extracts of OMK and MLA144 cells (containing the wild-type VDR) of equivalent protein concentration, B95–8 cell extract inhibited specific 1,25-(OH)2D3-VDR binding 84–86%. Sephadex G-100 gel filtration chromatography of the sterol binding component in the B95–8 cell extract detected a single peak of [3H]1,25-(OH)2D3 and [3H]25-OHD3 binding to a protein eluting with an apparent molecular mass of 58–60 kD. This 58–60 kD sterol binding component was also distinguished from the 50 kD VDR by its elution from DEAE-cellulose anion-exchange HPLC at 0.45 M KCl; the mammalian VDR eluted at 0.25 M KCl. These data suggest that the 1,25-(OH)2D3-resistant phenotype of B95–8 cells may be due to the presence of a relatively plentiful, 58–60 kD intracellular protein that binds 1,25-(OH)2D3 with low affinity but high capacity and inhibits the high-affinity nuclear localization of 1,25-(OH)2D3 to the VDR.
In vitro exposure to sodium fluoride does not modify activity or proliferation of human osteoblastic cells in primary cultures
Authors: Chavassieux Pascale , Chenu Chantal , Valentin-Opran Alexandre , Delmas Pierre D. , Boivin Georges , Chapuy Marie Claire , Meunier Pierre J. 
Published: February 2010

Abstract
The anabolic effects of sodium fluoride (NaF) on trabecular bone mass in osteoporosis is now well established. In vivo histologic studies performed in humans and other animals have shown that fluoride induces an increase in osteoblast number at the tissue level. To determine the mechanisms of action of fluoride on osteoblasts, we studied the effects of NaF on short- and long-term cultures of human osteoblastic cells derived from bone explants obtained from 21 donors. In short-term experiments, bone-derived cells were exposed to NaF for 4 days. At doses ranging from 10−11 to 10−5 M, NaF did not modify the alkaline phosphatase (AP) activity or osteocalcin secretion. In long-term experiments, half the bone samples from 15 donors were cultured for 4 months in the presence of 10−5 M NaF and the other half were maintained in NaF-free medium. Observations by light and electron microscopy disclosed no morphologic modification in bone ex-plants after 4 months of exposure to NaF, despite an increase in the bone fluoride content. After the first month of culture, slight but not significant increases were noted in 6 of 10 cases for AP activity, 4 of 10 for osteocalcin secretion, and 5 of 7 for [3H]thymidine incorporation. After 4 months of culture in the presence of NaF, no change in AP activity or cell proliferation was noted. In contrast, the osteocalcin secretion significantly decreased (p &lt; 0.05). These data suggest that, in vitro, under the conditions of this study, there is no direct effect of fluoride on the proliferation or activity (AP activity and osteocalcin secretion) of human osteoblastic cells and that this effect is very likely mediated by a cofactor.
Immunolocalization of noncollagenous bone matrix proteins in lumbar vertebrae from intact and surgically menopausal cynomolgus monkeys
Authors: Carlson Cathy S. , Tulli Hermina M. , Jayo Manuel J. , Loeser Richard F. , Tracy Russell P. , Mann Kenneth G. , Adams Michael R. 
Published: February 2010

Abstract
The noncollagenous matrix proteins, composing about 10% of the organic matrix of bone, are considered important for cell matrix organization and regulation of mineralization in bone. In the present study, seven of the major noncollagenous bone matrix proteins were localized immunohistochemically in serial sections of lumbar vertebrae from 24 (12 intact and 12 ovariectomized) adult female cynomolgus monkeys (Macaca fascicularis). Osteocalcin was the only protein restricted to bone cells and mineralized bone matrix. Bone sialoprotein was present in both bone and calcified cartilage, and all the other proteins were distributed in soft tissues as well as bone. Staining for both osteocalcin and bone sialoprotein was present diffusely throughout the bone matrix, but osteonectin, osteopontin, matrix gla protein, decorin, and biglycan staining was concentrated along bone surfaces. Osteoid was negative for osteocalcin and bone sialoprotein, but all other proteins had areas of positive immunostaining within osteoid. All proteins except biglycan exhibited strong immunostaining of a subset of active osteoblasts, suggesting that they may be markers of osteoblast maturity or state of activation. The pattern of immunostaining in intact and surgically menopausal monkeys was similar, except that staining for matrix proteins concentrated along bone surfaces appeared to be more widely distributed in the surgically menopausal monkeys, probably due to the higher rate of bone formation in these animals.
Pseudohypoparathyroidism with osteitis fibrosa cystica: Direct demonstration of skeletal responsiveness to parathyroid hormone in cells cultured from bone
Authors: Murray Timothy M. , Rao Leticia Gomez , Wong Min-Min , Waddell James P. , McBroom Robert , Tam Cherk S. , Rosen Fred , Levine Michael A. 
Published: February 2010

Abstract
A young girl had tibial osteotomies at age 14 for genu valgum and then had recurrent tibia) cysts over a number of years. Hypocalcemia and hyperphosphatemia were first noted at age 21. The diagnosis of pseudohypoparathyroidism was made at age 28, when elevated plasma PTH was detected. Clinical and biochemical features, including a PTH response test and assay of RBC Gs, established the diagnosis of pseudohypoparathyroidism type lb. Failure to suppress plasma PTH with vitamin D therapy led to an exacerbation of her cystic bone disease; there were widespread lytic lesions radiologically, most of which took up [99mTc]diphosphonate on bone scan. Microradioscopy revealed evidence of resorption of phalangeal tufts. Bone biopsy showed osteitis fibrosa cystica. During an orthopedic procedure, trabecular bone fragments were taken from her right humerus, and bone-derived cells cultured using an explant technique. The cultured cells were osteoblast-like in morphology, fully responsive to PTH, cholera toxin, forskolin, and PGE1 in vitro, and had an alkaline phosphatase and osteocalcin response to 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. Following this examination of skeletal responsiveness, attempts were made to suppress the elevated plasma PTH levels and symptomatic bone disease by optimizing therapy with oral 1,25-(OH)2D3. When bone pain associated with the cystic bone disease failed to resolve, the patient underwent total parathyroidectomy, following which the bone pain gradually resolved. This is the first direct demonstration of PTH responsiveness in cultured bone cells in the syndrome of pseudohypoparathyroidism with osteitis fibrosa cystica.
Detection of mRNA for carbonic anhydrase II in human osteoclast-like cells by in situ hybridization
Authors: Zheng Ming H. , Fan Ying , Wysocki Stan , Wood David J. , Papadimitriou John M. 
Published: February 2010

Abstract
Carbonic anhydrase II (CA II) plays an important role during osteoclastic bone resorption. Biochemical investigations of gene expression of CA II, however, have been hampered by difficulty in obtaining sufficient numbers of purified osteoclasts. In this study, we describe a nonradioactive, digoxigenin-labeled cDNA in situ hybridization technique capable of determining the pattern of CA II gene expression in human osteoclast-like cells (OC-like cells) at the single-cell level. The results showed that CA II mRNA was located in the cytoplasm of both imprinted and cultured OC-like cells from a giant cell tumor of bone. On the other hand, no evidence of CA II mRNA was found in either the mononuclear cells (tumor cells) of giant cell tumor of bone or osteosarcoma cells. There is a significant correlation between in situ hybridization and northern blot analysis for CA II mRNA in both the giant cell tumor of bone and the osteosarcoma. Our results also indicated that quantitation of in situ hybridization can be achieved by computed cytophotometry.
Proton channel part of vacuolar H+-ATPase and carbonic anhydrase II expression is stimulated in resorbing osteoclasts
Authors: Laitala Tuna , Väänänen Kalervo 
Published: February 2010

Abstract
Immobilization causes a transient increase in bone resorption and a prolonged depression of bone formation. We have studied the effect of immobilization on the expression of two proteins believed to have a major functional role in osteoclasts, the proteolipid subunit of vacuolar H+-ATPase (VPL) and carbonic anhydrase II (CA II). Trabecular bone from immobilized rat tibiae was analyzed using northern and slot blotting, polymerase chain reaction (PCR), and morphometric analysis. CA II and VPL transcription was rapidly stimulated in trabecular bone of immobilized rat tibiae. Osteoclast number increased and the trabecular bone volume decreased during immobilization. Fluorescein-labeled cDNA probes and a confocal laser scanning microscope were used to study the localization of VPL and CA II mRNAs in situ in osteoclasts and other bone-derived cells attached to bovine bone slices in vitro. CA II and VPL mRNA were highly expressed in actively resorbing osteoclasts, but in nonresorbing osteoclasts mRNA expression was very low or not detectable at all. These results strongly suggest that both CA II and VPL have an important functional role in bone resorption. Finally, in the bone cell population isolated for these studies, CA II was found to be highly specific for osteoclasts whereas VPL was also detected in other cell types.
A new method for vertebral fracture diagnosis
Authors: Ross Philip D. , Yhee Yhee K. , He Yi-Fan , Davis James W. , Kamimoto Carl , Epstein Robert S. , Wasnich Richard D. 
Published: February 2010

Abstract
A number of methods have been proposed for estimating the prevalence of vertebral fractures. Most methods are based on the distribution of normal vertebral dimensions in the population. However, these methods fail to identify a significant proportion (20–30% or more) of fractures documented on serial radiographs. This may occur because vertebral size varies between individuals as a result of differences in body size (and possibly other factors), and a normal range based on population reference data may be too large. In this paper, a new method is described for identifying vertebral fractures that are missed using diagnostic criteria based on vertebral dimension distributions of the population. This new method is based on calculating the average vertebral size, and statistical confidence limits, for the individual. The average vertebral size method was evaluated by testing its ability to identify incident fractures (which were identified from changes in dimensions compared to previous radiographs), using only the final film. The new method correctly identified most (81% of crush and 83% of wedge) incident fractures on the final radiograph. In contrast, criteria based on population distributions correctly identified only 53% of crush and 72% of wedge incident fractures. Using prospective data, prevalent fractures identified using both population-based and individual size-based criteria predicted the risk of incident fractures. Furthermore, incident fractures identified using both methods (population- and individual-based criteria) were associated with increased back pain. These data suggest that both types of prevalent deformities are important indicators of disease. We conclude that the new diagnostic method, which is based on an individual's vertebral size, will identify prevalent vertebral fractures missed by other methods and improve the accuracy of classification by fracture type (wedge, crush, and so on).
Improved treatment of paget's disease with dimethylaminohydroxypropylidene bisphosphonate
Authors: Schweitzer Dave H. , Zwinderman Aeilko H. , Vermeij Pieter , Bijvoet Olav L.M. , Papapoulos Socrates E. 
Published: February 2010

Abstract
A group of 89 patients with Paget's disease of bone were treated with different intravenous or oral doses of the nitrogen-containing bisphosphonate dimethylaminohydroxypropylidene bisphosphonate (dimethyl-APD). Biochemical remission was obtained in 82% of treatments, and in the rest a clear response was found. Oral dimethyl-APD was well tolerated, and a dose of 200 mg/day for 10 days was sufficient to induce remission in the majority of patients. The remission probability was 3 months for 50% of patients, and the recurrence-free period was 27 months. The remission probability as well as the recurrence-free period did not differ among oral and intravenous treatments or among patients who had never been treated with nitrogen-containing bisphosphonates and those who had received pamidronate in the past and were treated for a recurrence of the disease. Dimethyl-APD is a very effective bisphosphonate devoid of side effects, which given for a short period can induce long-lasting remissions in patients with Paget's disease of bone.
Differential expression of alkaline phosphatase in clones of human osteoblast-like cells
Authors: Dr. Manduca Paola , Sanguineti C. , Pistone M. , Boccignone E. , Sanguineti F. , Santolini F. , Federici A. 
Published: February 2010

Abstract
We established cultures of cells growing out from adult bone chips and maintained them through 12 passages in culture. The cultures showed osteoblastic phenotype accompanied by synthesis of collagen type I, osteonectin, alkaline phosphatase, and osteocalcin. We report the chracterization of 21 clones obtained from three different individual primary cultures. We studied the expression of osteonectin, alkaline phosphatase, collagen, and osteocalcin in the clones. Metabolic labeling showed production of type I collagen and of osteonectin in all clones studied. In two-thirds of the clones and in mass cultures alkaline phosphatase was not detected at passage 2, but it was detected in increasing amounts at later passages in culture. The clones attained different but detectable levels of expression of this marker by passage 8. The different levels in the expression of alkaline phosphatase in positive clones may be because they were derived from cells at different stages of osteoblastic maturation or due to small changes in microenvironment. The alkaline phosphatase-positive clones were tested for osteocalcin, and they showed measurable expression only at passage 10. A third of the clones obtained were negative for alkaline phosphatase during 12 passages in culture. The obtainment of clones unable to produce alkaline phosphatase may be due to loss of differentiating potential under the in vitro culture conditions. The growth rate and potential of all clones studied were similar through 12 passages in culture, regardless of their potential for expression of alkaline phosphatase.