bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bone matrix mRNA expression in differentiating fetal bovine osteoblasts
Authors: Ibaraki Kyomi , Termine John D. , Whitson S. William , Young Marian F. 
Published: February 2010

Abstract
In the accompanying study, we report an in vitro culture system from bovine bone cells that can be applied to investigate bone cell growth and differentiation. In this system, bovine bone cells placed in mineralization medium formed multilayers (days 2–3), began deposition of mineral (days 5–6), and eventually acquired a mineralized matrix sheet (days 14–20) through the stages of mineralizing nodules and trabecular-like structure. In the current study we used this system to investigate the relative expression of bone matrix genes that may play an important role in bone development and metabolism. α1(I)-collagen, alkaline phosphatase, osteonectin, biglycan (PgI), decorin (PgII), osteopontin, and bone sialoprotein mRNA gene expression were measured on days 0, 2, 6, 10, and 20 (date when the cells were placed in mineralization medium as day 0). Total RNA was purified and analyzed by northern blot using radiolabeled cDNA encoding these genes. To comprehend the relationship between gene expression and mineralization, total calcium content in the cultures was also measured. During the culture period we observed several very different gene expression profiles. The expression of both α1(I)-collagen and biglycan increased 3- to 4-fold by day 6 and then returned to basal levels by day 20. The osteonectin gene was highly expressed throughout the culture, with no significant increase in induction found during any time of culture. A significant induction of alkaline phosphatase (13.8-fold) gene expression was observed by day 6. Osteopontin showed a similar profile to that of alkaline phosphatase but had a much greater level of relative expression (26-fold) compared to day 0. Interestingly, downregulation during mineral accumulation seemed a common occurrence among many of the genes measured. In contrast, the bone sialoprotein gene showed a significant and distinct expression pattern, increasing rapidly after the onset of mineralization on day 6 and ultimately reaching 140-fold that of day 0. Decorin (Pg II) showed an increasing pattern, with the final relative level of induction 5-fold on day 20. These data suggest that the development of the mature osteoblastic phenotype, complete with the ability to produce a thick mineralized matrix, requires the differential regulation of a series of genes and their gene products over the culture period.
Bone mineral density in the proximal femur and hip fracture type in the elderly
Authors: Nakamura Norimasa , Kyou Takeshi , Takaoka Kunio , Ohzono Kenji , Ono Keiro 
Published: February 2010

Abstract
Bone mineral density (BMD) in the contralateral proximal femur in 100 female elderly patients with hip fracture and the 35 controls without hip fracture were investigated using dual-photon absorptiometry. The hip fracture patients were divided into intracapsular fracture (n = 53) and extracapsular fracture (n = 47) groups, and these two groups were further divided into five subgroups according to fracture site: intracapsular fracture type 1 (transcervical fracture, n = 29) and type 2 (subcapital fracture, n = 24); extracapsular fracture type 1 (intertrochanteric line fracture, n = 13), type 2 (pertrochanteric fracture, n = 28), and type 3 (combined type of pertrochanteric and subtrochanteric fracture, n = 6). The intracapsular fracture group showed BMD values similar to those of controls; the extracapsular fracture group showed significantly lower BMD values than controls. When these two were subclassified into five subgroups, different results were seen in terms of BMD value in the proximal femur and fracture types; intracapsular fracture type 1 showed BMD values equivalent to those of controls; on the other hand, type 2 showed significantly lower BMD value than controls, and the BMD distribution in the proximal femur among the extracapsular fracture subgroups 1–3 differed, although all of them showed significantly lower BMD values than controls. The degree of trauma causing the fractures was also assessed according to available anamnestic data, but no significant difference was found in trauma tendency between the intra- and the extracapsular fracture group or among the subgroups in each group. Based on these results, it is suggested that BMD distribution in the proximal femur is involved in determining hip fracture type in the elderly.
Establishment of the primary structure of the major lipid-dependent Ca2+ binding proteins of chicken growth plate cartilage matrix vesicles: Identity with anchorin cii (annexin V) and annexin II
Authors: Genge Brian R. , Cao Xu , Wu Licia N. Y. , Buzzi William R. , Showman Richard W. , Arsenault A. Larry , Ishikawa Yoshinori , Dr. Wuthier Roy E. 
Published: February 2010

Abstract
Electron microscopic studies of calcifying vertebrate tissues reveal the locus of de novo mineral formation within matrix vesicles (MV). The direct involvement of MV in the initiation of mineral formation is supported by the fact that MV isolated from avian growth plate cartilage rapidly accumulate large amounts of Ca2+ and Pi and induce mineral formation. Exploration of the constituents of MV has revealed two major protein components, a 33 and a 36 kD protein, the former of which binds to cartilage-specific collagens. These annexin-like proteins bind to acidic phospholipids in the presence of submicromolar levels of Ca2+. Antibodies raised against both the purified 33 and the 36 kD MV annexin do not cross-react with the other, indicating that they are distinct proteins. Reported here are studies elucidating the primary structure of both MV proteins using both conventional protein and molecular biologic methods. These studies establish that the 33 kD protein is nearly identical to anchorin CII (annexin V) and that the 36 kD protein is identical to avian annexin II. Immunolocalization studies show that hypertrophic chondrocytes at the calcification front of avian growth plate contain the highest level of these annexins. Further, immunogold labeling indicates that the annexins are localized within MV isolated from the growth plate. Recent studies indicate that annexin V is a new type of ion-selective Ca2+ channel protein that possesses selective collagen binding properties. Since MV are tightly associated with the collagen- and proteoglycan-rich matrix, it is tempting to speculate that this MV protein may be a component of stretch-activated ion channels that enhance Ca2+ uptake during mechanical stress.
Impact of short-term estrogen administration on growth hormone secretion and action: Distinct route-dependent effects on connective and bone tissue metabolism
Authors: Dr. Ho Ken K.Y. , Weissberger Andrew J. 
Published: February 2010

Abstract
We recently reported that estrogen exerts distinct effects on the GH/IGF-1 axis that are dependent on the route of delivery, probably reflecting a first-pass effect on hepatic IGF-1 production. Oral administration reduces IGF-1 and increases GH levels; transdermal administration elevates IGF-1 without changing GH concentrations. Since mesenchymal tissue is a target for GH and IGF-1 action, we studied changes in the GH/IGF-1 axis following oral (ethinyl estradiol, 20 μg/day) versus transdermal (Estraderm 100 TTS, Ciba Geigy, 100 μg 17β-estradiol per day) estrogen delivery and compared corresponding effects on connective and bone tissue metabolism. Mean 24 h GH levels, IGF-1, markers of fibroblast (procollagen III) and osteoblast (procollagen I, osteocalcin) function, and indices of bone turnover (fasting urinary hydroxyproline and calcium to creatinine ratios, UOHPr/Cr and UCa/Cr) were measured before and after 2 months of either oral or transdermal therapy in two groups of postmenopausal women. Transdermal estrogen administration significantly (p &lt; 0.05) increased IGF-1, procollagen III, procollagen I, osteocalcin, and UOHPr/Cr. In contrast, oral estrogen administration had a suppressive effect; the levels of IGF-1 (p = 0.001), procollagen III (p = 0.018), procollagen I (p = 0.002), osteocalcin (p = 0.015), and UOHPr/Cr (p = 0.004) were significantly different from those measured during transdermal administration. Both treatments significantly reduced UCa/Cr (p &lt; 0.015). IGF-1 changes during estrogen therapy were significantly related (p &lt; 0.05) to changes in procollagen III, procollagen I, osteocalcin, and UOHPr/Cr. Transdermally delivered estrogen stimulates IGF-1 production, increases osteoblastic function, and stimulates bone and nonbone collagen synthesis. When delivered orally, estrogen reduces IGF-1 and inhibits osteoblastic function; both routes suppress urinary calcium loss. Estrogen administration confers distinct route-dependent effects on connective and bone tissue metabolism; the specific effects on fibroblast and osteoblast function suggest IGF-1 dependency. The divergent effects on indices of bone turnover and connective tissue metabolism suggest that the route of estrogen replacement therapy may have different effects on the integrity of structural tissue in the menopause.
Detection of canine distemper virus in bone cells in the metaphyses of distemper-infected dogs
Authors: Mee Andrew P. , Webber David M. , May Christopher , Bennett David , Dr. Sharpe Paul T. , Anderson David C. 
Published: February 2010

Abstract
In the light of recent evidence implicating canine distemper virus (CDV) as a possible etiologic agent in Paget's disease of bone, we thought that it would be of interest to examine distemper-infected bone in the natural host. Samples from the long bones, spleen, and bladder of four distemper-infected and three uninfected dogs were examined for the presence of CDV nucleocapsid and phosphoprotein genes and the measles virus (MV) nucleocapsid gene using the technique of in situ hybridization with radioactively labeled riboprobes. Two of the four distemper-infected dogs showed strongly positive hybridization with both of the CDV probes. The signal was present in marrow cells, in osteoblasts, in osteocytes, and particularly in osteoclasts. No hybridization was seen over the cartilage cells of the growth plate, and there was a clear line of demarcation at the point of invasion of osteoclasts and vascularization. The spleen and bladder samples from infected dogs also showed positive hybridization. There was no hybridization with the MV probe in any of the distemper-infected tissue. Samples from the uninfected dogs showed no evidence of hybridization with either the CDV or MV probes. These results show that CDV can infect bone cells of the natural host and provide further support for the theory that CDV may play a role in human Paget's disease of bone.
Enhancement of osteoinduction by vitamin D metabolites in rachitic host rats
Authors: Atkin Isaac , Dean David D. , Muniz Ofelia E. , Agundez Agueda , Castiglione Greg , Cohen Galit , Howell David S. , Ornoy Asher 
Published: February 2010

Abstract
Diaphyseal bone from normal Sprague-Dawley rats was delipidated in chloroform-methanol and demineralized in 0.6 N HCl at 4°C. The bones were then implanted for 7–28 days into rats made rachitic by a low-phosphate, vitamin D-deficient diet (VDP−) for 3 weeks. Bones from VDP− and normal rats were also implanted into normal hosts. When normal rats were used as the host environment, a consistent sequence of cartilage induction and bone formation was observed. Demineralized rachitic bone (RB) implanted into normal host rats resulted in cartilage and bone induction similar to that seen for normal bone (NB) implants. Transmission electron microscopy of RB in normal hosts revealed morphologically normal chondrocytes and cartilage matrix with normal mineralization. In contrast, implantation of NB in VDP− hosts resulted in delayed chondrogenesis and lack of calcification. Furthermore, similar results were observed when RB was implanted into VDP− hosts. Treatment of VDP− hosts with either 1α-hydroxyvitamin D3 or 24,25-dihydroxyvitamin D3 did not accelerate the sequential appearance of precartilage or cartilage. However, 24,25-(OH)2D3 administered alone or in combination with 1α-OHD3 significantly increased the amount of calcified cartilage observed at 2 weeks postimplantation compared to implants from either untreated VDP− hosts or those treated only with 1α-OHD3. New bone formation was observed at 4 weeks postimplantation in all vitamin D-treated groups as determined by von Kossa staining or direct electron microscope examination. There was no apparent difference in the quantitative or qualitative bone formed within the various vitamin D-treated groups. Serum calcium and phosphorus levels were lower and alkaline phosphatase levels were higher in VDP− hosts compared with normal animals or those treated with vitamin D metabolites. The results of this study show a reduction in the capacity of progenitor cells in VDP− rat hosts to respond to osteoinductive factor(s). This impaired response appears to be corrected by vitamin D metabolites.
Evidence for the formation of a complex between osteopontin and osteocalcin
Authors: Ritter Nadine M. , Farach-Carson Mary C. , Butler William T. 
Published: February 2010

Abstract
We hypothesize that the mechanisms governing bone formation and remodeling involve the assembly of some of the components of the extracellular matrix into supramolecular complexes. We have examined the associations of osteopontin (OPN) with other proteins isolated from demineralized rat long bones. Three ligand binding techniques were used to demonstrate the formation of complexes between osteopontin and osteocalcin (OCN). Using gel overlay assays, the binding between soluble 125I-OPN and OCN immobilized in acrylamide gels was visualized. Competition for 125I-OPN-OCN complexes was demonstrated when unlabeled OCN-enriched bone extract was included in gel overlay solutions. Also, gel overlay assays showed 125I-OCN binding to OPN. Saturable binding was shown in solid-phase filter binding assays, which yielded an equilibrium binding constant of moderately high affinity (∼ 10−8 M). Specificity of OPN-OCN complex formation was confirmed by measuring binding in the presence of unlabeled OPN and OCN versus a bone-localized serum protein, α2HS-glycoprotein. Finally, the formation of soluble complexes were demonstrated in a modified Hummel-Dreyer gel filtration assay. These results indicate that OPN and OCN form complexes in vitro. The possible functions of OPN-OCN complexes in osteoclast recruitment and attachment are discussed.
The bisphosphonate, alendronate, prevents bone loss in ovariectomized baboons
Authors: Thompson D.D. , Seedor J.G. , Quartuccio H. , Solomon H. , Fioravanti C. , Davidson J. , Klein H. , Jackson R. , Clair J. , Frankenfield D. , Brown E. , Simmons H.A. , Rodan G.A. 
Published: February 2010

Abstract
We examined the effect of the amino bisphosphonate alendronate, administered IV every 2 weeks at 0.05 and 0.25 mg/kg for 1 year, on bone loss and parameters related to bone metabolism in ovariectomized baboons. Relative to non-OVX animals, the OVX baboons experienced increased bone turnover, reflected in biochemical and histomorphometric measurements, and bone loss assessed by dual-beam absorptiometry in the lumbar spine, which was similar to changes observed in ovariectomized women. Alendronate treatment maintained all parameters of bone turnover at control (nonovariectomized) levels and prevented the bone loss in a dose-dependent manner. We concluded that ovariectomized baboons offer a suitable model for the bone changes observed in ovariectomized women and that these changes can be prevented by sustained administration of an appropriate dose of this aminobisphosphonate.
Disodium 1-hydroxy-3-(1-pyrrolidinyl)-propylidene-1,1-bisphosphonate (EB-1053) is a potent inhibitor of bone resorption in vitro and in vivo
Authors: van der Pluijm Gabri , Binderup Lise , Bramm Erik , van derWee-Pals Lianne , de Groot Henny , Binderup Ernst , Löwik Clemens , Papapoulos Socrates 
Published: February 2010

Abstract
The ability of the new nitrogen-containing bisphosphonate disodium-1-hydroxy-3-(1-pyrrolidinyl)-propylidene-1,1-bisphosphonate (EB-1053) to inhibit osteoclastic resorption was examined in vitro and in vivo. Results were compared to those obtained with 3-amino-1-hydroxypropylidene-1,1-bisphosphonate (pamidronate or APD). In vitro, when tested in osteoclast precursor-dependent systems (fetal mouse metacarpals and a coculture system), EB-1053 suppressed 45Ca release effectively and was found to be about 10 times more potent than pamidronate (ED50 = 2.5 × 10−7 versus 2.5 × 10−6 M, respectively). The EB-1053-inhibited osteoclastic resorption could be reversed by treatment with parathyroid hormone (PTH). In vivo, daily subcutaneous injections of EB-1053 to young growing rats for 7 days increased metaphyseal bone mass in tibiae dose dependently. In these experiments EB-1053 was about 50 times more potent than pamidronate. These studies show that EB-1053 is a very potent bisphosphonate that has potential use in the treatment of skeletal disorders.
Neuroendocrine regulation of cyclic AMP formation in osteoblastic cell lines (UMR-106–01, ROS 17/2.8, MC3T3-E1, and Saos-2) and primary bone cells
Authors: Bjurholm Anders , Kreicbergs Andris , Schultzberg Marianne , Dr. Lerner Ulf H. 
Published: February 2010

Abstract
The effect of four different neuropeptides and norepinephrine (NE) on cyclic AMP formation in four different osteoblastic cell lines and in isolated neonatal mouse calvarial bone cells has been examined. In the rat osteosarcoma cell line UMR-106–01, vasoactive intestinal polypeptide (VIP, 0.001–1 μM), calcitonin gene-related peptide (CGRP, 0.3–30 nM), and NE (0.1–300 μM), but not neuropeptide Y (NPY, 0.001–1 μM) or substance P (SP, 0.1–10 μM), caused a dose-dependent stimulation of cyclic AMP formation. The stimulatory effects were synergistically potentiated by forskolin (0.1–3 μM). The effects of NE and VIP were time dependent, with an optimal effect seen at 5 minutes. The amount of cyclic AMP accumulated in cells stimulated with NE and VIP was in the same range. The amplitude of the cyclic AMP response induced by CGRP was smaller than that caused by VIP and NE. In the human osteosarcoma cell line Saos-2, NE (0.1 μM) and VIP (0.3 μM) stimulated cyclic AMP formation, and the effect was synergistically potentiated by forskolin. In the absence of forskolin, no effect of CGRP (30 nM) could be seen in the Saos-2 cells, but in the presence of forskolin (3 μM) a stimulatory effect was observed. SP and NPY did not change basal cyclic AMP levels in Saos-2 cells. In the osteoblastic osteosarcoma cell line of rat, ROS 17/2.8, NE (0.1 μM) caused a significant stimulatory action on cyclic AMP formation that was synergistically potentiated by forskolin (3 μM), VIP, CGRP, and SP did not affect the cellular content of cyclic AMP in ROS 17/2.8. In the mouse calvarial cell line MC3T3-E1 and in enzymatically isolated mouse calvarial bone cells, NE (0.1 μM), VIP (0.3 μM), and CGRP (30 nM), but not SP (10 μM) or NPY (1 μM), stimulated cyclic AMP formation. In UMR-106–01 cells and in isolated bone cells, but not in Saos-2 and ROS 17/2.8 cells, NPY (1 μM) inhibited the stimulatory effect of NE (0.3 μM) on cyclic AMP formation. These data show that osteoblastic cell lines are equipped with receptors for neuropeptides and NE. Since VIP, CGRP, NPY, and NE have been shown to occur in nerves of the skeleton, the observations in the present paper suggest the possibility that neurohormones may have a role in the regulation of osteoblastic activity.
Chronic adaptation of dog parathyroid function to a low-calcium-high-Sodium-Vitamin D-deficient diet
Authors: Cloutier M. , Gascon-Barré M. , D'Amour P. 
Published: February 2010

Abstract
The development of secondary hyperparathyroidism was studied in relation to changes in serum ionized Ca (Ca2+), 25-OHD, and 1,25-(OH)2D concentrations in six dogs maintained on a low-Ca (0.05%), high-Na (1.6%), and vitamin D-deficient diet for 91 weeks. Blood samples and evaluations of the parathyroid function were obtained before and after 3, 12, 24, 36, and 91 weeks of diet. Serum iPTH was measured by an intact hormone (I) and a carboxy-terminal (C) assay. The sigmoidal relationship between ionized Ca and iPTH values was evaluated mathematically. Results are means ± SD. Statistically significant changes over a time period were evaluated by an ANOVA for repeated measurements. Over the first 3 weeks, serum Ca2+, 25-OHD, and 1,25-(OH)2D did not change but stimulated I-iPTH increased 84.3 ± 39.9% (p &lt; 0.005) and C-iPTH only 25.3 ± 12.2% (p &lt; 0.01), a significant difference (p &lt; 0.02). The increase in stimulated I-iPTH reached 487.4 ± 139.6% (p &lt; 0.0001) and 418.4 ± 76.9% (p &lt; 0.0001) for C-iPTH by the end of the study. Similar significant increases were seen in basal and nonsuppressible iPTH at or after week 12. Serum 25-OHD concentration had decreased significantly at 12 weeks (0 = 99.9 ± 28.3 to 12 = 40 ± 6.8 nM, p &lt; 0.005) and even more so at 91 weeks (4.1 ± 0.3 nM, p &lt; 0.0005); this could be related to stimulated I-iPTH at 12 weeks (r = −0.5472, p &lt; 0.02) and thereafter, even though 25-OHD does not have a direct effect on the parathyroid glands. Even if serum Ca2+ had only decreased at week 36 (0 = 1.36 ± 0.02 to 36 = 1.32 ± 0.02 mM, p &lt; 0.05), it could be inversely related to stimulated I-iPTH from week 24 (r = −0.4290, p &lt; 0.05). Serum 1,25-(OH)2D increased up to 24 weeks (0 = 109.7 ± 20.7 to 24 = 173.4 ± 28.7 pM, p &lt; 0.0005) at which time it was positively related to stimulated I-iPTH (r = 0.506, p &lt; 0.02); it then decreased to slightly below basal level by week 91 (82.7 ± 8.6 pM). Despite these two added stimuli, progression of the parathyroid function did not accelerate after week 24. In conclusion, dietary changes appear to be the main factor stimulating secondary hyperparathyroidism in this model. The addition of a low serum Ca2+ and a relatively low level of 1,25-(OH)2D did not enhance the effect of the diet.
Assessment of spinal and femoral bone density by Dual X-Ray absorptiometry: Comparison of lunar and hologic instruments
Authors: Dr. Pocock Nicholas A. , Sambrook Philip N. , Nguyen Tuan , Kelly Paul , Freund Judith , Eisman John A. 
Published: February 2010

Abstract
Clinical application of techniques for assessing bone mineral density (BMD) requires accurate and precise measurements that can be related to clearly defined normal ranges. In this study we investigated the clinical interpretation of BMD values in a group of individuals measured on the same day with two different dual-energy x-ray densitometers (Lunar DPX and Hologic QDR 1000). The BMD results were analyzed as absolute values in g/cm2 and with respect to young and age-specific normals as defined by each manufacturer. Absolute BMD values measured by the two instruments were highly correlated (lumbar spine r = 0.98, femoral neck r = 0.95; p &lt; 0.0001). In the lumbar spine, the two instruments assigned almost identical values when expressed as a percentage of age-matched values and as a percentage of young normals, despite a small but systematic difference between the values assigned for the latter index. In the femoral neck, however, there were significant differences in assignments between instruments, expressed both as a percentage of young normal (mean difference 6.2%) and with respect to age-matched values (mean difference 3.3%). In particular, in premenopausal subjects femoral neck values with the Hologic instrument were assigned significantly lower values. This study shows effective comnparability between these two instruments for absolute and relative values for the lumbar spine, as well as for absolute values at the femoral neck, but important differences for normality assignments at the femoral neck. These latter differences may produce bias in the “diagnosis” of femoral neck osteoporosis and may have important implications for clinical decision making. Until these differences are resolved, clinicians should not rely solely on femoral neck BMD measurements in clinical decision making.