bluuebunny/crossref_metadata_2025_split huggingface dataset:
Insulinlike growth factor II and transforming growth factor β regulate collagen expression in human osteoblastlike cells in vitro
Authors: Dr. Strong Donna D. , Beachler Anthony L. , Wergedal Jon E. , Linkhart Thomas A. 
Published: February 2010

Abstract
Insulinlike growth factor II (IGF-II) and transforming growth factor β (TGF-β) are the most abundant polypeptide growth factors found in human bone matrix and are produced by human bone cells in vitro. IGF-II and TGF-β, increased total protein synthesis, collagenous protein synthesis, and the steady-state level of type I procollagen mRNA in a time-dependent manner in osteoblastlike cells isolated from human bone. Type III procollagen mRNA expression was low in untreated cultures and was not affected by IGF-II or TGF-β. TGF-β, elevated type I procollagen mRNA rapidly, with the maximal observed change at 10 h. In contrast, procollagen mRNA levels increased more slowly in response to IGF-II and reached a lower maximal level than with TGF-β, but the response was sustained through 24 h. Collagenous protein synthesis in IGF-II- and TGF-β-treated cells increased in parallel with increases in procollagen mRNA levels and was higher at 21 h for TGF-β, and at 36 h for IGF-II. The difference in the time course and magnitude of change in type I procollagen mRNA levels in response to IGF-II and TGF-β, suggests that these two growth factors work through distinct mechanisms that provide both a rapid transient response and a later sustained response in bone matrix biosynthetic activity.
In vitro resorptive activity of isolated chick osteoclasts: Effects of carbonic anhydrase inhibition
Authors: Dr. Hunter Susan J. , Rosen Clifford J. , Gay Carol V. 
Published: February 2010

Abstract
A potent inhibitor of carbonic anhydrase, 5-[3-hydroxybenzoyl]thiophene-2-sulfonamide (HTS), was shown to cause a 37% reduction in the area of resorption pits formed by isolated chick osteoclasts when used at a dose of 10−7 M. HTS at doses of 10−9 and 10−7 M was also effective in reducing acid formation by the osteoclasts (14 and 36%, respectively). Additionally, the effect of HTS was found to be readily reversed by removing the agent, showing that it does not exert a toxic effect on the cells. This study indicates that the inhibitory effect of HTS on bone resorption is at the level of the acid-forming mechanism in osteoclasts and supports the view that carbonic anhydrase has a central role in the process.
Bone mass in an urban and a rural population: A comparative, population-based study in Southern Sweden
Authors: Dr. Gärdsell Per , Johnell Olof , Nilsson Bo E. , Sernbo Ingemar 
Published: February 2010

Abstract
Several previous studies have reported regional differences in the incidence of hip fractures. A population-based study was performed in the city of Malmö (urban population) and in the municipality of Sjöbo (rural population), 60 km apart. A total of 961 men and women, randomly selected and of Scandinavian ethnic background, participated in the study. Bone mineral content (BMC) of the forearm was measured with single-photon absorptiometry (SPA).
Women and men in the city had significantly lower BMC compared with the rural population. The differences were even more pronounced when comparing a true urban population (lived their entire life in a city) with a true rural population (never lived in a city). The differences in BMC between Malmö and Sjöbo were more obvious in men.
These data suggest that differences in bone mass between an urban and a rural population could to some extent explain differences in fracture incidence.
Structural requirements for the action of parathyroid hormone-related protein (PTHrP) on bone resorption by isolated osteoclasts
Authors: Evely Roger S. , Bonomo Anthony , Schneider Hans-Gerhard , Moseley Jane M. , Gallagher James , Professor Martin T. John 
Published: February 2010

Abstract
Parathyroid hormone-related protein (PTHrP) plays a major role in the syndrome of humoral hypercalcemia of malignancy (HHM) by its actions on bone and kidney. In this study an isolated osteoclast bone resorption assay was used to investigate the actions of this peptide and the structure-activity relationships for its resorption effect. As with PTH, neither synthetic nor recombinant PTHrP preparations stimulated resorption within highly purified osteoclast populations. Resorption was stimulated only in the presence of contaminating osteoblasts or in cocultures with the osteoblastlike cell line UMR-106. In the presence of osteoblasts PTHrP-(1–34) and PTHrP-(1–84) stimulated bone resorption in a dose-dependent manner with a potency comparable to that of PTH-(1–34) on a molar basis. The biologic activity of the PTHrP was shown to reside in the first 34 amino acids, and within that region the structural requirements for promotion of osteoclastic resorption resembled closely those for promotion of cyclic AMP formation in osteoblastlike cells. Using emulsion autoradiography with iodinated PTHrP-(1–34) and PTHrP-(1–84) on mixed bone cell preparations from neonatal rats, specific binding was demonstrated only to osteoblasts, not to osteoclasts. These results clearly demonstrate that PTHrP is a potent stimulator of bone resorption and that these effects are, like those of PTH, mediated by initial actions upon cells of the osteoblast lineage.
Calcium regulation of parathyroid and C cell function in familial benign hypercalcemia
Authors: Rajala Mary M. , Klee George G. , Heath Hunter 
Published: February 2010

Abstract
The roles of parathyroid hormone (PTH) and calcitonin (CT) in the pathogenesis of familial benign hypercalcemia (FBH, or hypocalciuric hypercalcemia) are uncertain. Thus we performed studies in 26 patients with FBH, 12 patients with primary hyperparathyroidism (HPT), and 20 normal volunteers, to answer these questions: are plasma levels of intact or biologically active PTH frequently elevated in FBH? Is plasma intact PTH nonsuppressible during calcium infusion? Is there blunting of the C cell CT response to calcium infusion as occurs in primary HPT? We used three methods for measurement of PTH: a mid region-specific radioimmunoassay (iPTH, antiserum GP-1M), an extraction-concentration bioassay (bioPTH, stimulation of cAMP generation in osteoblastlike cells), and a two-site immunoradiometric assay (IRMA) for intact PTH. PTH levels were significantly elevated in primary HPT by all three methods, but mean PTH was normal in FBH and 85–92% of values overlapped the normal range. During 5 minute calcium infusions (2 mg Ca2+ per kg) iPTH values fell little, but bioPTH and intact PTH fell sharply in all three groups. Mean calcium-induced decreases of intact and bioPTH were indistinguishable from normal in FBH, but PTH levels generally remained elevated at 5 minutes in primary HPT. In FBH basal and postinfusion CT levels were normal. The data show that, in the majority of patients with FBH, PTH concentrations and bioactivity in blood are within the normal range and are suppressed rapidly to very low levels with further increases of calcium. The data suggest that the abnormality of parathyroid function in FBH differs from that in primary HPT. There was no deficiency of CT or C cell responsiveness in FBH, another difference from primary HPT. Nonetheless, in 8–15% of cases, measurement of PTH could not discriminate FBH from primary HPT.
Effect of prostaglandins E1, E2, and F2α on osteoclast formation in mouse bone marrow cultures
Authors: Collins David A. , Chambers Timothy J. 
Published: February 2010

Abstract
Prostaglandins (PG) act as direct inhibitors of mature osteoclasts, but although resorption-inhibition is also observed initially PG increase bone resorption in organ culture. This suggests that PG influence bone resorption in organ culture through actions on cell types other than mature osteoclasts. We have therefore tested the effects of PG E1, E2, and F2α on the differentiation of osteoclastic phenotype in mouse bone marrow cultures using bone resorption and calcitonin receptors (CTR) as markers of osteoclastic differentiation. We found that PGE2 (10−6–10−9 M) and PGE1 (10−6–10−7 M) induced a significant increase in CTR-positive cell numbers, to levels five to eight times those seen in controls and similar to the number induced by 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. Bone resorption was increased (10−7 M PGE2 and 10−6 M PGE1) in association with the increased CTR-positive cell numbers, suggesting that the PG also induced resorptive function. 1,25-(OH)2D3 increased both the number of CTR-positive cells and the extent of resorption per cell; the additional presence of PG did not affect the number of CTR-positive cells but did reduce bone resorption compared with 1,25-(OH)2D3 alone. PGF2α had no significant effect on CTR-positive cell induction or bone resorption. The results suggest that PGE1 and E2 induce osteoclastic differentiation in mouse bone marrow cultures and inhibit the function of the osteoclasts thus formed. The explanation for this apparently paradoxical behavior may be that osteoclast generation occurs in a different microenvironment from that in which osteoclast function is regulated and that PG production may be inversely modulated at the two sites, in response to a given stimulus, to effect a change in bone resorption.
Amino-terminal sequence homology of two chick kidney mitochondrial proteins immunoisolated with monoclonal antibodies to the cytochrome P450 of 25-hydroxyvitamin D3-1α-hydroxylase
Authors: Moorthy Bhagavatula , Mandel Mark L. , Ghazarian Jacob G. 
Published: February 2010

Abstract
We demonstrate the unique capability of monoclonal antibodies for the specific immunodetection and characterization of two antigenic proteins occurring in normal chick kidney mitochondrial extracts. The antigens were adsorbed to cyanogen bromide-activated Sepharose gel coupled to monoclonal antibodies (MAbs) of the IgM class raised against cytochrome P4501α, which inhibit equally the 25-hydroxyvitamin D3 1α- and 24-hydroxylase catalytic activities (Mandel et al. 1990 J Clin Lab Immunol, in press). The two identified antigenic proteins are polypeptides with apparent molecular weights of 57,000 and 55,000 daltons. The 1α-hydroxylase cytochrome P450 has been shown to have a molecular weight of 57,000 daltons (Mandel et al. 1990 Biochim Biophys Acta 1034:239–246). The optimal antigen: Gel ratio for maximal antigen binding as cytochrome P450 heme, which was determined spectrally, was found to be 1.3 nmol cytochrome P450 per g MAb- coupled Sepharose. At this ratio the total binding capacity of the gel was 1 nmol cytochrome P450 per g Sepharose. The two polypeptides were desorbed with 0.1% Emulgen 911 in 25% glycerol at pH 3.0 and separated by SDS-gel electrophoresis. The amino-terminal sequences of the two antigens were determined by automated Edman degradation with an on-line analyzer of PTH derivatives. The sequences in both antigens were 100% homologous. Complete amino acid composition analysis also revealed that their amino acid compositions were highly similar. These findings suggest that the smaller protein may be a proteolytic cleavage product of the 1α-hydroxylase P450 cytochrome and may represent a putative 24-hydroxylase antigen.
Classification of vertebral fractures
Authors: Eastell Richard , Cedel Sandra L. , Wahner Heinz W. , Riggs B. Lawrence , Dr. Melton L. Joseph 
Published: February 2010

Abstract
Although it is a cardinal feature of involutional osteoporosis, there is often disagreement on what constitutes a vertebral fracture. We measured vertebrae T4-L5 in 52 healthy women to develop a normal range (mean ± 3 SD) for vertebral shape and used these data to assess the prevalence of vertebral fractures. We classified vertebral fractures by type of deformity (wedge, biconcavity, or compression) and further by the degree of deformity (grades 1 and 2). In 195 postmenopausal women who were an age-stratified random sample of the Rochester population (ages 47–94), 40 (21%) had vertebral fractures (mean, 2 per person). There was a similar number of compression and wedge fractures, and grade 2 fractures were as common as grade 1. In a referral sample of 74 women with suspected osteoporosis, 62 (84%) had vertebral fractures (mean, 3.3 per person). Wedge fractures were most common, and grade 2 fractures were more common than grade 1. The distribution of type and grade of fractures differed between the two patient groups (P &lt; 0.01). Bone mineral density of the lumbar spine was related to mean fracture grade (r = −0.33, P &lt; 0.05) and to fracture number (r = −0.57, P &lt; 0.001) but not to fracture type. We conclude that a comprehensive approach is required in describing vertebral fractures. Using this approach we found distortion in the fracture characteristics of women referred to an osteoporosis clinic compared to women in the community.
Enzymatic isolation of chondrocytes from immature rabbit articular cartilage and maintenance of phenotypic expression in culture
Authors: Glade Michael J. , Kanwar Yasphal S. , Hefley Thomas J. 
Published: February 2010

Abstract
The studies included here identify factors affecting cartilage digestion by crude bacterial collagenase (cCGN) and describe a cartilage digestion medium that maximizes both tissue digestion rate and viable cell yield. The basal digestion medium contained 100 mM NaCl, 3 mM K2HPO4, 1 mM CaCl2, 1 mM MgSO4, 10 mM NaHCO3, 60 mM sorbitol, 5 mg/ml of dextrose, 1 mg/ml of albumin, and 2 mg/ml of cCGN in 25 mM HEPES at pH 7.2. Approximately 45% of articular cartilage tissue was digested in this basal medium in 6 h at 37°C, yielding 6.8 × 106 viable cells per g tissue digested. The addition of 30 μM tosyllysylchloromethane (TLCM) increased the fraction of tissue digested in 6 h to 68% (p &lt; 0.05) and doubled viable cell yields to 13.6 × 106 per g tissue digested (p &lt; 0.05). Withholding Mg, decreasing NaCl to 70 mM, and adding 30 mM KCl increased fractional tissue digestion to 81% (p &lt; 0.01) and doubled viable cell yield yet again (to 29.9 × 106 viable cells per g tissue digested). Supplementation with TLCM increased the rate of cartilage digestion and the yield of viable cells regardless of cCGN source or lot. Additional trypsin (0.25%) inhibited tissue digestion and decreased cell yield; this effect was reversible with the addition of TLCM. The cartilage digestion medium developed in these studies (low Mg with added K and TLCM) was very effective in digesting articular, scapular, rib, and growth plate cartilage, as well as in yielding a large number of viable chondrocytes. These cells grew well in culture and maintained their chondrocytic characteristics, secreting predominantly type II collagen and large macromolecular forms of chondroitin sulfate-rich proteoglycans.
Spine deformity index (SDI) versus other objective procedures of vertebral fracture identification in patients with osteoporosis: A comparative study
Authors: Sauer Peter , Leidig Gudrun , Minne Helmut W. , Duckeck Günter , Schwarz Wolfgang , Siromachkostov Lubomir , Ziegler Reinhard 
Published: February 2010

Abstract
Radiologic identification of vertebral fractures is most important in the diagnosis and monitoring of patients with spinal osteoporosis. Different methods, using vertebral height measurements for fracture identification, have therefore been developed. We compared four methods for fracture identification in spinal x-rays of 62 female patients with primary osteoporosis. The methods of Hedlund and Gallagher,(1) Melton et al.,(2) and Davies et al.(3) are based on the ratio of heights within one vertebra or of the height ratios of adjacent vertebrae; all three methods result in counting the number of vertebral fractures. The fourth method of Minne et al.(4) relates anterior, middle and posterior heights of the vertebrae between T5 and L5 to the respective heights of T4. The relative vertebral heights of patients with osteoporosis are compared to the respective relative heights (anterior, middle, and posterior) of normal subjects (T5-L5). This allows the identification of fractured vertebrae, as well as a quantification of the extent of deformation due to these fractures (spine deformity index, SDI).
The same measurement data of 62 spinal x-rays of anterior, middle, and posterior heights between T4 and L5 were used to detect vertebral fractures by the four different methods. Correlation between the number of identified fractures by the different methods ranged between r = 0.56 and 0.83. On the other hand, we found a remarkable difference in the mean number of identified fractures and a discrepancy in the identification of single vertebrae as fractured or not. All four methods revealed an accumulation of fractures in the midthoracic area and in the region of transition from thoracic to lumbar spine. Vertebral fractures as identified by SDI were not detected by the other three methods in 12–29% of the cases, even if vertebral height reduction was more than 6 mm. The reliability of each method was examined by the determination of “decreasing” number of fractures during follow-up. A decrease in the number of fractures was found in about 25% patients, if using the three methods(1–3) that count only the number of fractures. We obtained a 3.6% decrease in the number of fractures using the fourth method.(4) Furthermore, the decrease in SDI values in follow-up was within the range of variance.
We therefore believe that SDI and related procedures are reliable in quantifying spinal osteoporosis and monitoring during follow-up.
Assessment by reflection ultrasound method of the effect of intermittent slow-release sodium fluoride-calcium citrate therapy on material strength of bone
Authors: Dr. Zerwekh Joseph E. , Antich Peter P. , Sakhaee Khashayar , Gonzales Jerome , Gottschalk Frank , Pak Charles Y. C. 
Published: February 2010

Abstract
It has been suggested that fluoride therapy, while increasing bone mass, produces bone with inferior mechanical properties. In the present report this hypothesis was tested using a novel reflection ultrasound technique. Transiliac crest bone biopsies were obtained from 16 patients with osteoporosis and vertebral compression fractures (12 women and 4 men, mean age 56 years) before and after approximately 2 years of intermittent slow-release sodium fluoride therapy (25 mg twice a day) combined with continuous calcium citrate supplementation. Samples were analyzed by a reflection ultrasound method, which analyzes ultrasound velocity with a sample site resolution of 200 μm and thus provides a measure of the mechanical property of single trabeculae (material). For the group, mean fractional change in velocity increased 6.1 ± 2.3% (SEM) from a mean value of 3303 ± 80 to 3484 ± 55 m/s (p = 0.028). A total of 13 patients (81%) demonstrated higher velocities after treatment. Thus reflection ultrasound analysis of bone appears to provide a sensitive means of assessing changes in the material property of bone. Furthermore, these results suggest that the treatment regimen utilized in these patients improves strength of bone at the material or trabecular level largely independently of change in bone mass. The combination therapy also increased spinal (L2-L4) bone density for the group as assessed by dual-photon absorptiometry (5.3 ± 2.0%). There was no significant correlation between the change in ultrasound velocity and bone density (r = 0.0026, p = 0.996). This finding supports the suggestion that the strength of whole vertebrae (structure) could also have been increased following treatment as a result of a rise in bone mass, possibly from an increased number of trabeculae. Taken together the results support the possibility that intermittent slow-release sodium fluoride treatment in combination with calcium citrate can enhance the strength of whole bone (spine) by improving the microscopic or material property of bone, as well as by increasing bone mass.
Iron as a possible aggravating factor for osteopathy in itai-itai disease, a disease associated with chronic cadmium intoxication
Authors: Noda Makoto , Yasuda Masanori , Kitagawa Masanobu 
Published: February 2010

Abstract
Itai-itai disease is thought to be the result of chronic cadmium (Cd) intoxication. We examined 23 autopsy cases of itai-itai disease and 18 cases of sudden death as controls. Urine and blood samples from 10 patients were collected before they died and revealed the presence of severe anemia and renal tubular injuries. Undecalcified sections of iliac bone were stained with Aluminon reagent, an ammonium salt of aurintricarboxylic acid, and Prussian blue reagent in all cases of itai-itai disease. These two reagents reacted at the same mineralization fronts. X-ray microanalysis revealed the presence of iron at mineralization fronts in itai-itai disease. Five patients showed evidence of hemosiderosis in the liver, spleen, and pancreas, probably as a result of post transfusion iron overload. Renal calculi and calcified aortic walls were also stained with Prussian blue reagent in several patients. Neither ferritin nor transferrin were visualized at mineralization fronts in itai-itai disease by immunohistochemical staining. These results suggest that iron is bound to calcium or to calcium phosphate by a physicochemical reaction. A marked osteomalacia was observed in 10 cases of itai-itai disease by histomorphometry. Regression analyses of data from cases of itai-itai disease suggested that an Aluminon-positive metal inhibited mineralization and that renal tubules were injured. Since bone Cd levels were increased in itai-itai disease, it is likely that renal tubules were injured by exposure to Cd. Therefore, stainable bone iron is another possible aggravating factor for osteopathy in itai-itai disease, and a synergistic effect between iron and Cd on mineralization is proposed.
Coexistence of reduced function of natural killer cells and osteoclasts in two distinct osteopetrotic mutations in the rat
Authors: Dr. Popoff Steven N. , Jackson Mary E. , Koevary Steven B. , Marks Sandy C. 
Published: February 2010

Abstract
Recent evidence suggesting that immune cells and their products (cytokines) play an important role in the regulation of skeletal development and function, particularly of the osteoclast, implies that immune cell dysfunction may be involved in the pathogenesis of certain skeletal disorders. The mammalian osteopetroses are a pathogenetically heterogeneous group of skeletal disorders characterized by skeletal sclerosis resulting from reduced osteoclast-mediated bone resorption. Using a 51Cr-release microcytotoxicity assay we demonstrated that splenic natural killer (NK) cell activity was significantly reduced in two distinctly different osteopetrotic mutations in the rat, osteopetrosis (op) and toothless (tl). To determine whether this reduction in NK cell-mediated cytotoxicity is caused by decreased cell number and/or function in these osteopetrotic mutants, we quantitated NK cells by analyzing mononuclear cell suspensions labeled for two-color fluorescence with OX8 and OX 19 monoclonal antibodies in a fluorescence-activated cell sorter. Flow cytometry of these double-labeled cells revealed that the percentage of NK cells (OX8+/OX19− subset) in op and tl spleens was not significantly different from that of normal spleens. These results suggest that NK cells in these osteopetrotic mutants are functionally defective. Thus aberrations in osteoclast and NK cell function coexist in these mutations, and their developmental relationships deserve further study.