bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of intrinsic bone quality in vivo by reflection ultrasound: Correction of impaired quality with slow-release sodium fluoride and calcium citrate
Authors: Antich Peter P. , Pak Charles Y.C. , Gonzales Jerome , Anderson Jon , Sakhaee Khashayar , Rubin Craig 
Published: February 2010

Abstract
The intrinsic (material) quality of cancellous and cortical bone was evaluated in vivo from the measurement of reflection ultrasound velocities in the ulna. In cancellous bone, the reflection ultrasound velocity was inversely correlated with age in normal women (r = −0.48, p = 0.001), with a significantly lower mean value in 32 normal postmenopausal women than in 14 premenopausal women (3124 versus 3341 m/s, p &lt; 0.0001). In 32 untreated osteoporotic women the cancellous bone velocity was lower than in normal postmenopausal subjects (2906 versus 3124 m/s, p = 0.0001). Following treatment with slow-release sodium fluoride plus calcium citrate (mean 2.4 years in 33 osteoporotic patients with no fracture during treatment), the cancellous bone velocity was significantly higher than in untreated osteoporotic women (3082 versus 2906 m/s, p = 0.0002) and was not significantly different from that in normal postmenopausal women. The cortical bone velocity displayed similar trends, but the changes did not attain statistical significance. The measurements were repeated approximately 9 months later in 9 untreated and in 20 treated patients; in 5 additional patients, the measurements were made both before and after 9 months of treatment with slow-release sodium fluoride and calcium citrate. The cancellous bone velocity increased significantly (p = 0.046) in these patients, from 3008 m/s before treatment to 3112 m/s after the first 9 months of treatment. The velocity rose significantly from 3037 to 3167 m/s (p = 0.017) in patients treated for a short time (12–30 months at first measurement), but it did not change in untreated patients or those treated for more than 30 months. Thus, the material quality of cancellous bone decreases with normal aging and is reduced further with the osteoporotic process. This impaired quality may be corrected by treatment with slow-release sodium fluoride plus calcium citrate.
Effect of medium pH on osteoclast activity and osteoclast formation in cultures of dispersed rabbit osteoclasts
Authors: Shibutani Toshiaki , Dr. Heersche Johannes N.M. 
Published: February 2010

Abstract
We investigated the effect of medium pH on activity of isolated osteoclasts and have also looked at the possibility that medium pH affects osteoclast numbers during culture. Osteoclast-containing cell suspensions prepared from neonatal rabbits were cultured on bovine bone slices at pH 6.5, 7.0, or 7.5. After 24 or 48 h of culture, the cells and bone slices were fixed and stained for tartrate-resistant acid phosphatase (TRAP). After counting the osteoclasts, the cells were removed and the resorption lacunae stained by immunostaining using anticollagen type I antibody and then quantitated. We found that the resorptive activity of isolated rabbit osteoclasts was sharply increased at pH 6.5–7. Osteoclast differentiation and proliferation, on the other hand, were optimal at pH 7.0–7.5 but decreased at pH 6.5. The results thus imply that pH regulation of the bone surface environment can dramatically alter both the number of osteoclasts and their resorptive activity.
Bone disease in burn patients
Authors: Klein Gordon L. , Herndon David N. , Rutan Thomas C. , Sherrard Donald J. , Coburn Jack W. , Langman Craig B. , Thomas Mary L. , Haddad John G. , Cooper Cary W. , Miller Nancy L. , Alfrey Allen C. 
Published: February 2010

Abstract
Burn patients are at risk for bone disease due to aluminum (AI) exposure from use of antacids and albumin, partial immobilization, and increased production of endogenous glucocorticoids. Moreover, severely burned children are growth impaired up to 3 years after the burn. To determine the extent of bone disease, we studied nine men and three women, ages 18–41 years, with greater than 50% body surface area burn. Seven patients underwent iliac crest bone biopsy following double tetracycline labeling, one additional patient expired after a single label, and three others had postmortem specimens obtained for quantitative AI only. Serial serum and urine samples were obtained weekly until biopsy or death. All biopsied patients had reduced bone formation and osteoid area, surface, and width, with mineral apposition rate, osteoblast surface, and osteoclast number with normal eroded surfaces compared to age- and sex-matched normal ambulatory volunteers. Burn patients also had reduced bone formation, mineral apposition rate, osteoid area, and surface compared to age-matched volunteers at short-term bed rest. Serum levels of osteocalcin were low. Most patients had mild hypercalcemia but only a third had hypercalciuria. All patients had elevated AI in blood or urine; urine AI correlated inversely with serum osteocalcin. In 60% significant bone AI was detectable by stain or quantitation. Our data are compatible with burn patients having markedly reduced bone turnover. AI loading, partial immobilization, endogenous corticosteroids, and cytokine production may be among the etiologic factors.
Effect of ovariectomy on bone response to in vivo external loading
Authors: Hagino Hiroshi , Raab Diane M. , Kimmel Donald B. , Akhter Mohammed P. , Recker Robert R. 
Published: February 2010

Abstract
This study was undertaken to find whether the bone response to increased external loading (EL) of the tibia in rats is affected by estrogen depletion. Female Sprague-Dawley rats 6 months were randomly assigned to four groups of 10 each: sham ovariectomy without loading (Shm-XL), ovariectomy without loading (OVX-XL), sham ovariectomy with external loading (Shm-EL), and ovariectomy with external loading (OVX-EL). In vivo external loading by a four-point bending device was initiated 4 weeks after surgery. The right lower leg of each EL rat was loaded at 31.4 ± 0.2 N for 36 cycles at 2 Hz every other day for 21 days (11 loading days). Mean in vivo induced strain was 1305 microstrain (μϵ) for Shm-EL rats and 1280μϵ for OVX-EL rats. With external loading of the tibia, periosteal bone formation rose equally in Shm and OVX rats. Woven bone was present around the tibia or fibula in 60% of the loaded rats and none of the control rats. No loading response occurred either at the endocortical surface or in the cancellous bone of the proximal tibial metaphysis. After OVX, cancellous bone area in the proximal metaphysis declined and formation surface rose compared to Shm rats. Although periosteal and endocortical bone formation rose after OVX, no cortical bone loss occurred. We conclude that ovariectomy and attendant loss of endogenous estrogen do not change the cortical bone response to an external load of about 1300μϵ in rats. However, these results may not predict the cortical bone response to loading in animals with Haversian remodeling that display estrogen-related loss of cortical bone.
Molecular cloning and sequence analysis of cDNA for a 59 kD bone sialoprotein of the rat: Demonstration that it is a counterpart of human α2-HS glycoprotein and bovine fetuin
Authors: Ohnishi Tomokazu , Nakamura Osamu , Ozawa Masayuki , Arakaki Naokatu , Muramatsu Takashi , Daikuhara Yasushi 
Published: February 2010

Abstract
A complementary DNA (cDNA) for the 59 kD bone sialoprotein, which is supposed to be the rat counterpart of human α2-HS glycoprotein (α2-HSG) and is synthesized by both hepatocytes and osteoblasts, has been cloned from a rat liver cDNA library. Polyclonal rabbit antibodies to rat 59 kD bone sialoprotein were used to identify and isolate the cDNA. The amino acid sequence of 59 kD bone sialoprotein deduced from the cDNA revealed that the entire protein consisted of 352 amino acid residues, including a signal peptide of 18 amino acid residues, and contained three possible N-glycosylation sites. On Northern blot analysis of rat liver, an mRNA of about 1.5 kilobases was detected. An mRNA of 59 kD bone sialoprotein was also detectable in rat bone but not in other tissues, such as kidney, brain, and lung. A computer search of protein and nucleic acid data bases revealed that 68.2, 63.2, and 97.4% amino acid residues of 59 kD bone sialoprotein were identical with those of human α2-HSG, bovine fetuin, and rat phosphorylated N-glycoprotein (pp63), respectively. The positions of cysteine residues in 59 kD bone sialoprotein also completely matched those in human α2-HSG and bovine fetuin, indicating that the sialoprotein is the rat counterpart of human α2-HSG and bovine fetuin. In addition, comparison of the nucleotide sequence of cDNA for rat fetuin/α2-HSG with that for pp63 recently corrected showed only two differences in nucleotides in the entire protein coding regions of the two proteins, and immunoreactive rat fetuin/α2-HSG in the conditioned medium of adult rat hepatocytes in primary culture was found to be phosphorylated. Thus, because rat fetuin/α2-HSG isolated from bone and synthesized by osteoblasts in culture does not contain phosphorus, it seems to be pp63 dephosphorylated during circulation or in the bone matrix.
Insulin-like growth factor binding protein–4 inhibits both basal and IGF-mediated chick pelvic cartilage growth in vitro
Authors: Schiltz Patric M. , Dr. Mohan Subburaman , Baylink David J. 
Published: February 2010

Abstract
This laboratory has purified a unique insulin-like growth factor binding protein (IGFBP-4) that was previously demonstrated to be inhibitory to bone cell proliferation. In this study, the hypothesis that IGFBP-4 is inhibitory to insulin-like growth factor (IGF) actions on cartilage was tested using the pelvic cartilages of 10-day-old chick embryos as an in vitro model system. Pelvic leaflets were incubated in serum-free medium for 18 h with effectors (BSA, IGF-I, IGF-II, IGFBP-4, or a combination of IGF and IGFBP-4). After the first 8 h, 1.5 μCi [3H]thymidine per well was added. Cartilage growth was assayed by TCA-insoluble [3H]thymidine incorporation into DNA. Additional experiments were conducted under similar conditions to assess the actions of the effectors on cartilage dry weight over a 72 h time period. In separate experiments, serum-free medium conditioned by chick pelvic cartilages for 72 h was assayed for IGF-II by radioreceptorassay, IGF-I by radioimmunoassay, and IGFBP by western ligand analysis. Exogenous IGF addition increased [3H]thymidine incorporation and dry weight of cartilages compared to controls. IGFBP-4 decreased both parameters in basal cartilage growth and also inhibited IGF-mediated cartilage growth. Pelvic cartilages secreted in vitro both IGF-I and IGF-II and a 32–34 kD IGFBP. In conclusion, the IGFs are stimulatory to cartilage growth in vitro and embryonic chick cartilage in vitro produces both IGF-I and II as well as an IGFBP. Exogenous IGFBP-4 inhibits both the basal and IGF-mediated growth of chick cartilage, suggesting that IGFBP-4 acts to downregulate the growth-promoting effects of IGFs on cartilage growth.
Longitudinal study of bone mass in end-stage renal disease patients: Effects of parathyroidectomy for renal osteodystrophy
Authors: Copley John B. , Hui Siu L. , Leapman Stephen , Slemenda Charles W. , Johnston Conrad C. 
Published: February 2010

Abstract
The effectiveness of parathyroidectomy (PTHX) for the control of secondary hyperparathyroidism was assessed in 46 adult end-stage renal disease (ESRD) patients whose bone mineral content at the midshaft and distal radius was measured using single-photon absorptiometry (SPA) every 6 months before and after the surgery. They were compared to 46 age-, race-, and sex-matched ESRD patient controls who had not undergone surgery but who had had at least five SPA studies at similar intervals. Presurgery midradius bone mass was significantly lower for PTHX patients compared to controls. Comparing changes in bone mass of PTHX patients across surgery to controls in comparable time periods showed that PTHX patients lost significantly less bone mass after surgery. Similar results were obtained when rates of change in bone mass were evaluated. When patient characteristics were examined, the effect of surgery was found to be diminished in elderly patients and in oophorectomized patients. It is concluded that PTHX can have a salutary effect on renal osteodystrophy in the appendicular skeleton, but factors other than bone mass also need to be considered in identifying those patients who will benefit from surgery.
High-dose estrogen inhibits bone resorption and stimulates bone formation in the ovariectomized mouse
Authors: Bain Steven D. , Bailey Mason C. , Celino Darlene L. , Lantry Megan M. , Edwards Martin W. 
Published: February 2010

Abstract
In This Study, We Have Investigated Estrogen'S Capacity To Regulate Bone Formation And Resorption In The Ovariectomized Mouse, Evaluating The Dose And Site Dependence Of Estrogen Action On Bone Modeling And Remodeling Surfaces. To Quantitate Bone Resorption, The Skeletons Of Fifty 8-Week-Old Swiss-Webster Mice Were Prelabeled With [3H]tetracycline (3H-T) before initiation of treatment protocols. Ovariectomies (OVX) and sham surgeries were performed 3 days after the final 3H-T injection, and the animals were assigned to treatment groups and injected once per week for 4 weeks with one of the following doses of 17β-estradiol (E2): sham/oil vehicle (SV), OVX/oil vehicle, OVX/50 μg E2, OVX/250 μg E2, and OVX/500 μg E2. To assess bone formation, fluorochrome labels were administered 9 and 2 days before sacrifice. At the conclusion of the 4 week protocol, the femora and thoracic vertebrae were removed to quantitate the levels of bone resorption based on the skeletal retention of 3H-T. The tibiae were excised for histomorphometric evaluation of the proximal metaphyses and middiaphyses. Indicative of increased bone resorption, vehicle-treated OVX animals had significantly reduced levels of 3H-T in femora and vertebrae compared to SV mice. This result was consistent with histomorphometric data showing a 49% decrease in cancellous bone area of the proximal tibiae in the OVX/oil-treated group. Treatment of OVX animals with 50 μg E2 was sufficient to maintain 3H-T levels in vertebrae at SV values, with higher E2 doses leading to a dose-dependent increase in the retention of 3H-T at this site. In contrast, 3H-T levels in the femora of mice treated with 50 and 250 μg E2 were intermediate between the SV- and vehicle-treated OVX animals. Only at 500 μg E2 per week were 3H-T values in femora maintained at SV values compared to OVX mice treated with vehicle. Histology data indicated that treatment of OVX mice with 250 μg E2 prevented osteopenia in the proximal metaphyses of the tibiae; the 500 μg dose of E2 led to a fivefold increase in cancellous bone volume compared to SV mice. In OVX mice treated with 500 μg E2, cancellous bone formation rates were increased 83% compared to SV animals and 35% compared to the OVX/oil-treated group. These increases were a consequence of increased bone-forming surface. E2 treatment also stimulated bone formation on the endosteal surface of the diaphysis. In summary, these results indicate that E2 inhibits bone resorption in femora and vertebrae of OVX mice in a dose-dependent fashion and has the capacity to stimulate bone formation on both endosteal and cancellous bone surfaces.
Interaction of parathyroid hormone-related peptide-responsive dual signal transduction systems in osteoblastic osteosarcoma cells: Role in PTHrP-induced homologous desensitization
Authors: Sugimoto Toshitsugu , Kano Junichi , Ikeda Kazuto , Fukase Masaaki , Chihara Kazuo 
Published: February 2010

Abstract
In Osteoblastic Umr-106 Cells, 10−7 M human (h) PTH-related peptide (PTHrP)-(1–34) significantly induced the formation of total inositol phosphates to the same degree as 10−7 M hPTH-(1–34), confirming that in addition to cAMP-dependent protein kinase (PKA), PTHrP possesses another signal transduction system, calcium/protein kinase C (Ca/PKC). Experiments were therefore performed to characterize the cross talk of these dual-signal transduction systems and its participation in the PTHrP-induced homologous desensitization of cAMP and cytosolic calcium (Cai) response in osteoblasts. Preincubation with 10−7 M hPTHrP-(1–34) caused homologous desensitization, resulting in a remarkable decrease in cAMP accumulation in response to further exposure to PTHrP. This effect was significant after 2 h pretreatment and reached a maximum at 6 h. Pretreatment with the PKC-activating phorbol ester phorbol 12-myristate-13-acetate (PMA, 10−6 M) for 30 minutes and 6 h caused a significant increase and decrease in cAMP responsiveness to PTHrP, respectively. Pretreatment with calcium ionophores (A23187 or ionomycin, 10−6 M), not for 30 minutes but for 6 h, caused a significant decrease in cAMP responsiveness to PTHrP. H-7 (an inhibitor of PKC, 50 μM) significantly blocked not only PMA- but also PTHrP-induced desensitization of the cAMP response. PTHrP caused the complete homologous desensitization of an increase in Cai within 30 minutes. Pretreatment with dibutyryl-cAMP (10−4 M) for 30 minutes caused significant inhibition of the PTHrP-induced increase in Cai, and pretreatment with Sp-cAMPS (10−4 M), a direct activator of PKA, for 30 minutes completely blocked the PTHrP-induced increase in Cai. Rp-cAMPS (10−4 M), an antagonist in the activation of PKA, slightly but significantly antagonized the PTHrP-induced homologous desensitization of the Cai response. The present study demonstrated the existence of cross-talk in PTHrP-responsive dual signal transduction systems and its participation in PTHrP-induced homologous desensitization.
CGRP Radioreceptor assay: A new diagnostic tool for medullary thyroid carcinoma
Authors: Wimalawansa Sunil J. 
Published: February 2010

Abstract
The Quantitative Analysis Of Immunoreactive Calcitonin (Ict) Is The Assay Of Choice For Diagnosis And Follow-Up Of Patients With Medullary Thryoid Carcinoma (Mtc). However, In A Small Percentage Of Patients With Mtc Or C Cell Hyperplasia (Cch), Basal And Stimulated Ict Levels May Not Be Significantly Elevated. In These Patients, Calcitonin Gene-Related Peptide (Cgrp) Radioreceptor Assay (Rra) Can Be Used Complementary To Immunoassay For Ct (Or Katacalcin) For Prompt Diagnosis Of Mtc And Cch. Cgrp Rra Is A Robust, Rapid, Sensitive, And Specific Determinant Of “Receptor-Recognized” Cgrp (Rr-Cgrp; Intact Molecule Of Cgrp) Either In Plasma Or In Tissue Extracts. Plasma Rr-Cgrp Levels Rose &gt; 100% 2–5 Minutes After Stimulation With Intravenous Pentagastrin (Calcium Or Oral Alcohol) (P &lt; 0.001), Whereas Icgrp Levels Were Raised To A Lesser Degree (P &lt; 0.01). In Six Patients Who Had A False Positive Ict Response After Pentagastrin Or Had Raised Basal Ict Levels Measured With A Two-Site Immunoradiometric Assay, Rr-Cgrp Showed Only A Minimal Change. On The Other Hand, In Patients With Cch (True Positive, N = 8), Ict Was Increased By Only 40% After Pentagastrin But Rr-Cgrp Levels Rose By 140% (P &lt; 0.001). No Change In Ict Or Rr-Cgrp Levels In Plasma Were Detected In Healthy Normal Volunteers After Administration Of Pentagastrin. Therefore, In Addition To The Plasma Ict Levels, Rr-Cgrp Would Resolve Some Of The Difficult Diagnostic Problems Associated With Mtc And Likely Improve The Specificity And Sensitivity Of Identifying Cch.
Molecular Cloning Of A Plasma Membrane Calcium Pump From Human Osteoblasts
Authors: Kumar Rajiv , Haugen James D. , Penniston John T. 
Published: February 2010

Abstract
The osteoblast plays a critical role in bone formation, bone remodeling, bone matrix formation, and matrix calcification. To better understand the process of osteoblast-controlled bone formation, we determined the structure and isoform types of the plasma membrane calcium pump from normal human osteoblasts. A complementary DNA library from normal human osteoblasts was screened for plasma membrane calcium pump clones. Sequencing and analysis of cDNA clones revealed the presence of a 3986 base pair cDNA that encoded a 1220 amino acid protein that was similar to the human plasma membrane calcium pump isoform 1. Polyadenylated RNA from human osteoblast cells contains bands of RNA approximately 5050 and 6750 bases long. Reverse transcription of polyadenylated RNA from human osteoblasts followed by amplification of the RNA-DNA duplex with calcium pump isoform-specific primers revealed the presence of isoforms 1 and 2 of the calcium pump. Isoform 4 was not detected. We conclude that normal adult human osteoblasts contain a plasma membrane calcium pump that is similar to the human plasma membrane calcium pump isoform 1. It is likely that this pump plays an important role in the cell biology of the human osteoblast.
Menatetrenone inhibits bone resorption partly through inhibition of PGE2 synthesis in vitro
Authors: Hara Kuniko , Akiyama Yasuhiro , Tajima Tetsuya , Shiraki Masataka 
Published: February 2010

Abstract
We studied the effect of menatetrenone, a vitamin K2 homolog, on bone resorption stimulated by interleukin-1α (IL-1α), prostaglandin E2 (PGE2), parathyroid hormone (PTH), and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. Bone-resorbing activity was assessed by measurement of calcium and hydroxyproline in the media and calvariae. IL-1α (0.1–100 U/ml), 1,25-(OH)2D3 (1010-10−7 M), PGE2 (10−9-10−6 M), and PTH (3 × 10−8-3 × 10−7 M) dose dependently increased the levels of calcium and hydroxyproline in the medium. Indomethacin (10−6 M) completely inhibited bone resorption induced by IL-1α and partially inhibited bone resorption induced by 1,25-(OH)2D3. However, indomethacin did not affect the action of PGE2 or PTH. Menatetrenone (3 × 10−6-3 × 10−5 M) inhibited the bone resorption induced by IL-1α (2 U/ml), PGE2 (10−7 M), PTH (3 × 10−7 M), and 1,25-(OH)2D3 (3 × 10−10 M) in a dose-dependent manner. Menatetrenone also inhibited the PGE2 production stimulated by IL-1α. These results indicate that menatetrenone may inhibit bone resorption through at least two different mechanisms; one possibly is an inhibitory effect on prostaglandin production.
Pertussis toxin-sensitive activation of phospholipase A2 can be resolved from phosphoinositidase C in primary cultures of mouse osteoblasts using indomethacin
Authors: Sandy Jonathan R. , Meikle Murray C. , Farndale Richard W. 
Published: February 2010

Abstract
Recent work has established that various bone-resorbing hormones are able to activate phosphoinositide metabolism as well as eicosanoid production in osteoblast-like cells, although the relationship between these pathways is unclear. We used pertussis toxin and indomethacin to inhibit the stimulation of [3H]arachidonic acid release and [3H]phosphoinositide turnover caused by treating primary cultures of mouse osteoblasts with fetal calf serum. We found (1) that pertussis toxin and indomethacin each inhibited both pathways and (2) that although pertussis toxin inhibited [3H]arachidonic acid release to a greater extent than indomethacin, [3H]inositol phosphate accumulation was inhibited rather more effectively by indomethacin. These data suggest that whereas ligands in fetal calf serum activate [3H]arachidonic acid release largely directly via the action of a pertussis-sensitive G protein, activation of phosphoinositidase C is indirect, being substantially dependent upon eicosanoid production. These experiments suggest that serial activation of phospholipase A2 and phosphoinositidase C may occur in osteoblasts and that only the former enzyme is regulated by a pertussis toxin-sensitive G protein.