bluuebunny/crossref_metadata_2025_split huggingface dataset:
Journal of Bone and Mineral Research
Authors: Warner J. , Dr. Clifton-Bligh P. , Posen S. , McElduff A. , Delbridge L. , Reeve T. 
Published: February 2010

Abstract
Forearm bone mineral content was measured in 28 patients with primary hyperparathyroidism before and 1 year after successful parathyroidectomy. The forearm bone mineral content rose from a mean value of 1.068 to 1.092 g/cm (P &lt; 0.05, paired /-test). Those patients with the lower initial values had the largest rise. In an additional study, the forearm bone mineral content was measured in 10 women over the age of 40 years (mean age 58.6 ± 7.9SD years) with hyperparathyroidism before and for 2 years after successful parathyroidectomy and compared with the forearm bone mineral content measured over 2 years in 12 women (mean age 56.3 ± 5.5SD years) with continuing hyperparathyroidism and with the forearm bone mineral content of 12 eucalcemic control women (mean age 58.8 ± 8.2SD years), also measured over 2 years. The parathyroidectomized group gained bone, whereas the ongoing hyperparathyroid group and the eucalcemic control group lost bone. The difference between the parathyroidectomized group and the ongoing hyperparathyroid group was significant after 2 years (P &lt; 0.05). The percentage loss of forearm bone mineral in the eucalcemic control subjects was not significantly different from the percentage loss of forearm bone mineral in the ongoing hyperparathyroid group, although the initial mean bone mineral content in the eucalcemic group was significantly higher than in the ongoing hyperparathyroid group, suggesting that a possible determinant of bone mineral loss in women in this age group is the initial bone mineral content.
Journal of Bone and Mineral Research
Authors: Dr. Parfitt Michael A. , Rao D. Sudhaker , Kleerekoper Michael 
Published: February 2010

Abstract
The sustained effects of biochemical screening to increase both apparent incidence and age at diagnosis indicate that, without screening, most patients with primary hyperparathyroidism would never be diagnosed. This suggests that asymptomatic patients discovered as a result of screening have a nonprogressive form of the disease, with adverse health effects that are few or nontraditional, for which treatment policies validated only in symptomatic patients may be inappropriate. Accordingly, in 1975 we formulated criteria for withholding surgical treatment from such patients. Of 174 who were eligible for study over a 10 year period, clinical, biochemical, and densitometric assessment was repeated after at least 1 year (mean 52 months) in 106 patients who did not differ in any initial characteristic from 68 patients in whom follow-up was inadequate. There was no change in symptoms, no disease complications, and no change in any index of hormone secretion or disease severity. In 30 patients, individual regression slopes against time were not significant for any serum measurement. In these patients the disease appeared to have stopped progressing by the time the diagnosis was made, most likely because of cessation of tumor growth. There was a significant deficit in appendicular cortical bone at the time of diagnosis but no further acceleration of bone loss thereafter. In an earlier study, surgical cure was followed by a modest increase in forearm bone density for the first 6 months, but even after 3 years only about 20% of the deficit was corrected. The deficit in bone density is smaller in the spine than in the forearm and is not accompanied by any increase in vertebral fracture risk. Our data suggest that surgery may not be needed to prevent the traditional complications of primary hyperparathyroidism in asymptomatic patients, but our study is weakened by deficiency in follow-up and lack of concurrent control subjects. Also, nontraditional effects on cardiovascular mortality, cancer incidence, and neurobehavioral morbidity were not addressed. Resolution of these uncertainties requires a controlled clinical trial of surgical versus conservative management in these patients.
Journal of Bone and Mineral Research
Authors: Dr. Heath David A. , Heath Eileen M. 
Published: February 2010

Abstract
The personal management of patients seen with primary hyperparathyroidism over the past 10 years has been reviewed; 248 cases were identified of which 122 have been managed conservatively. These patients were mainly asymptomatic. Apart from 4 who developed renal stones, which were spontaneously passed, there was no clinical or biochemical evidence that patients sustained adverse consequences by conservative management. These studies support the need for further studies of the conservative management of asymptomatic hyperparathyroidism.
Journal of Bone and Mineral Research
Authors: Shane Elizabeth 
Published: February 2010

Abstract
Patients with mild asymptomatic primary hyperparathyroidism who do not meet currently accepted guidelines for surgery may be followed medically. General medical management of these individuals should be directed toward maintaining adequate hydration, therapy of hypertension, and avoiding immobilization. Diuretics should be used only with caution. Moderate dietary calcium intake (500–800 mg/day) should be encouraged. Propranolol and cimetidine are not useful in the therapy of primary hyperparathyroidism. Oral phosphate is efficacious in lowering serum and urinary calcium. However, because of concerns related to ectopic calcification, phosphate is usually reserved for those patients who meet surgical guidelines but who are not to undergo surgery. Bisphosphonates, potent inhibitors of osteoclast-mediated bone resorption, have been shown to lower serum and urinary calcium in patients with primary hyperparathyroidism. However, long-term data on their efficacy in this disorder are not yet available. The use of bisphosphonates at the present time is generally restricted to the research setting. More potent bisphosphonates as well as the design of newer agents that interfere with parathyroid hormone secretion may become very useful in future approaches to the medical management of primary hyperparathyroidism.
Journal of Bone and Mineral Research
Authors: Wells Samuel A. 
Published: February 2010

Abstract
Primary hyperparathyroidism was thought 30 years ago to be a rare disease, and the diagnosis was most often made in patients presenting with either bone disease or kidney stones. Today the minority of patients with hyperparathyroidism present with such symptoms, a fact accounted for by the introduction into general medical practice three decades ago of laboratory technology for efficiently determining the serum concentrations of various blood minerals, including calcium. Hypercalcemia was detected more frequently, and it was realized that most patients with hyperparathyroidism either had minor symptoms, such as constipation, polyuria, tiredness, and muscle weakness, or they were “asymptomatic” and indistinguishable from normal subjects. It was thought that primary hyperparathyroidism was a progressive disease and that sooner or later all patients would become symptomatic and require parathyroidectomy. Since this operation was curative in a high percentage of cases, it was recommended for virtually all patients once the diagnosis was established. In this contribution the long-term benefits of parathyroidectomy in patients with and without symptoms from primary hyperparathyroidism are reviewed. It is concluded that a multicenter prospective randomized trial is needed to resolve the indications for operative and nonoperative management of patients with this disease.
Journal of Bone and Mineral Research
Authors: Doppman John L. , Miller Donald L. 
Published: February 2010

Abstract
A number of recently published series were reviewed evaluating noninvasive localizing studies (ultrasound, thallium-technetium subtraction scintigraphy, computed tomography, and magnetic resonance imaging) in patients with primary hyperparathyroidism and no previous surgery. The average true positive (%) and false positive (%) rates were (1) ultrasound, 66 and 12; (2) Th/Tc scanning 55 and 13; (3) computed tomography, 63 and inadequately documented; (4) magnetic resonance imaging, 75 and 18. The success rate of initial operation in this group of patients is over 90%. There is no evidence that preoperative localizing studies shorten operating time or prevent surgical failures. For these reasons, noninvasive localization studies are not indicated in patients with primary hyperparathyroidism before initial surgery.
Development and characterization of a rapidly proliferating, well-differentiated cell line derived from normal adult human osteoblast-like cells transfected with SV40 large T antigen
Authors: Keeting Philip E. , Scott Robert E. , Colvard Douglas S. , Anderson Marlys A. , Oursler Merry J. , Spelsberg Thomas C. , Dr. Riggs Lawrence B. 
Published: February 2010

Abstract
A new bone cell line was established by transfecting normal adult human osteoblast-like (hOB) cells, derived from a 68-year-old woman, with the plasmid pSV3 neo. The plasmid included coding sequences and promotors for the large and small T antigens of the SV40 virus as well as resistance to the antibiotics neomycin and G418. A single antibiotic-resistant colony was located and cloned. Large tumor antigen production in the clonal cell line was confirmed by indirect immunofluorescence study. Treatment with 1,25-dihydroxy-vitamin D3 increased steady-state concentrations of protein and mRNA for osteocalcin and for alkaline phosphatase. Northern blot analyses also demonstrated the presence of mRNAs for α(I)-procollagen, osteopontin 1a, transforming growth factor β, and interleukin-1β. The plasma membrane calcium pump and osteonectin were identified by immunocytochemical analysis. These cells produced a matrix that mineralized when β-glycerophosphate was added to their cultures. As assessed by functional receptor assays, both estrogen and androgen receptors were present and functional, although at low concentrations. Treatment with parathyroid hormone did not stimulate adenylate cyclase activity. Thus, these cells are a well-differentiated, steroid-responsive clonal cell line that closely approximates the phenotype of the mature osteoblast. They should serve as an excellent model for the study of osteoblast biology.
Radial bone mineral changes in pre- and postmenopausal healthy japanese women: Cross-sectional and longitudinal studies
Authors: Hagino Hiroshi , Yamamoto Kichizo , Teshima Ryota , Kishimoto Hideaki , Kagawa Takeshi 
Published: February 2010

Abstract
Healthy premenopausal and postmenopausal Japanese women were evaluated by longitudinal and cross-sectional studies to assess changes in radial bone mineral density. A total of 300 healthy Japanese women were enrolled in the cross-sectional study, and 126 of them were chosen for the longitudinal study. In the cross-sectional study significantly lower bone mineral density was found in the women over 50 years old. In the longitudinal study, premenopausal women aged 45–54 years showed rate of change of -0.61%/year at the distal radius and 0.49%/year at the radial shaft. The perimenopausal changes were –1.95 and -0.93%/year and the postmenopausal changes were –1.88 and –1.37%/year at the distal radius and at the radial shaft, respectively, in the women aged 45–54 years. These rates of premenopausal and postmenopausal change were similar to those reported for whites in the United States. The strength of the relationship between the rate of change in radial bone mineral density and the anthropometric values, biochemical data, and menopausal status was evaluated by multiple linear regression analysis. Menopausal status had the greatest influence on the rate of change in radial bone mineral density. It is concluded that menopausal status was the most important variable related to bone loss in our longitudinal study and the rate of bone loss was greatest during the early postmenopausal period in healthy Japanese women.
Immunohistochemical identification of superoxide dismutases, catalase, and glutathione-s-transferases in rat femora
Authors: Deahl S. Thomas , Oberley Larry W. , Oberley Terry D. , Elwell James H. 
Published: February 2010

Abstract
We used light microscopic immunohistochemistry to locate manganese superoxide dismutase, copper zinc superoxide dismutase, catalase, and glutathione-S-transferases in demineralized femora from rats of 4–14 weeks of age. Immunoblots confirmed the specificity of the polyclonal antibodies for the rat proteins of interest. Each of the enzymes exhibited a unique staining pattern. Copper-zinc superoxide dismutase was detected within some articular and epiphyseal chondrocytes of younger animals. Manganese superoxide dismutase was detected within some articular and epiphyseal chondrocytes, within some osteoprogenitor cells and osteoblasts, within many osteoclasts, and within some vascular smooth muscle cells. Catalase was identified within articular chondrocytes, epiphyseal chondrocytes, and osteocytes, whereas staining at the periphery of hypertrophic chondrocytes suggested extracellular and/or cell membrane-associted catalase. Glutathione-S-transferases were detected within and at the periphery of epiphyseal and articular chondrocytes and less prominently within cortical osteocytes. There were no major age-related changes in antioxidant enzyme distribution.
Interaction of nascent preproparathyroid hormone molecules with microsomal membranes
Authors: Baba Hisamitsu , Karaplis Andrew C. , Wiren Kristine M. , Keutmann Henry T. , Kronenberg Henry M. 
Published: February 2010

Abstract
To characterize the early steps in the interaction of nascent chains of preproparathyroid hormone (prepro-PTH) with the secretory apparatus, such truncated nascent chains still attached to ribosomes were tested for binding to microsomal membranes and cleavage by signal peptidase. Nascent chains of 114, 97, 88, 81, 70, and 59 residues were tested for their ability to bind tightly to membranes and to undergo signal sequence cleavage. Chains of 81 residues and longer bound tightly to the membranes and were cleaved by signal peptidase. The 88- and 81-residue precursors and their corresponding pro-proteins were less efficiently associated with the membranes than were the 114- and 97-residue precursors and their corresponding pro-proteins. The 70-residue chain bound to the membrane but was not cleaved. When this peptide was subsequently released from the ribosome with puromycin, it was cleaved by signal peptidase. The 59-residue chain bound only slightly to the microsomal membrane and was not cleaved by signal peptidase, even when the nascent peptide was released from the ribosome with puromycin. Thus the critical length for productive binding to microsomal membranes is between 59 and 70 residues; the length required for signal cleavage is between 70 and 81 residues.
Expression of insulin-like growth factor I messenger ribonucleic acid in regenerating bone after fracture: Influence of indomethacin
Authors: Edwall Dan , Prisell P.T. , Levinovitz A. , Jennische E. , Norstedt G. 
Published: February 2010

Abstract
Expression of insulin-like growth factor I (IGF-I) was studied during time in the callus formed after tibial fracture in rats. Levels of IGF-I mRNA in callus peaked on the day 8 postfracture, showing a 10- to 15-fold induction compared to control bone. Levels of IGF-I mRNA tended also to be increased in the fracture-adjacent musculus tibialis anterior. IGF-I immunoreactivity was found in cartilaginous cells, osteoblasts, and myocytes 6 and 8 days after fracture. No obvious differences were found between hypophysectomized animals and control animals with regard to IGF-I immunoreactivity. Administration of the antiinflammatory drug indomethacin decreased the IGF-I mRNA expression in the tibial fracture model. Previous findings have shown that IGF-I is activated during in vivo muscle regeneration, and also in this model indomethacin administration reduces the expression of IGF-I. The finding that indomethacin administration reduces IGF-I expression could indicate that an inflammatory response may be important for activation of IGF-I during tissue regeneration.
A new sensitive homologous radioimmunoassay for amino-terminal parathyroid hormone in the rat
Authors: Finch Jane L. , Rapp Neville , Martin Kevin J. , Slatopolsky Eduardo 
Published: February 2010

Abstract
The determination of circulating biologically active PTH in the rat has been difficult due at least in part to the inability to develop an antibody suitable for RIA of rat PTH. However, since the amino acid sequence of the rat PTH molecule has been deduced by molecular techniques, corresponding synthetic peptides have made it possible to produce such an antibody. A total of 12 roosters were immunized with synthetic rat PTH-(1–34), and one animal, RD1, developed a sensitive antibody against this amino-terminal region of the rat PTH molecule. To further increase the sensitivity of the RIA, we utilized an analog of rat PTH, Tyr1 rat PTH-(2–34), as the radioligand, which can be iodinated to high specific activity (450 μCi/μg). The iodinated peptide was purified by HPLC using a C18 Nova Pak HPLC column and a 20–60% acetonitrile gradient in 0.1% TFA. Synthetic rat PTH-(1–34) was used as the standard. To validate the RIA, we measured PTH under a variety of metabolic conditions. Normal values for PTH were 55.6 ± 3.9 pg/ml (n = 26). Levels in parathyroidectomized (PTX) rats (n = 9) were undetectable, but renal insufficiency and vitamin D deficiency increased PTH to 587.4 ± 141.3 pg/ml (n = 73) and 1662.0 ± 137.8 (n = 27), respectively. Intraperitoneal (IP) administration of ethylenediaminetetraacetic acid (EDTA), 200 mg/kg, was used to decrease ionized calcium (ICa) from 4.75 ± 0.07 to 3.55 ± 0.10 mg/dl, which increased PTH from 51.3 ± 5.9 to 109.3 ± 13.4 pg/ml (n = 12). During calcium administration (30 mg/kg) IP, serum ICa increased from 4.69 ± 0.05 to 7.26 ± 0.24 mg/dl and PTH became rapidly undetectable (n = 14). Dietary manipulation (low Ca 0.02% and high PO4 2.0%) for 3 weeks increased PTH from 43.2 ± 3.2 to 71.9 ± 11.4 pg/ml (n = 13). In conclusion, we have developed a specific, sensitive, homologous RIA directed against the biologically active region of the rat PTH molecule. Rapid changes in PTH in response to physiologic stimuli are readily quantitated with this assay, which will be a useful tool for the assessment of parathyroid function in the intact rat.
Sequential and precise in vivo measurement of bone mineral density in rats using dual-energy x-ray absorptiometry
Authors: Ammann Patrick , Dr. Rizzoli René , Slosman Daniel , Bonjour Jean-Philippe 
Published: February 2010

Abstract
In the design of new strategies for the treatment of osteoporosis, noninvasive, precise, and sensitive bone mass measurement capable of detecting changes over short periods of time in small animals is essential. Most of the models described thus far require the sacrifice of the animals and/or display low reproducibility. Using a dual-energy x-ray absorptiometer (DEXA; Hologic QDR-1000) in an ultrahigh-resolution mode, we measured bone mineral density (BMD) in rats at the levels of lumbar spine (L1–4), proximal tail (caudal vertebrae C2–4), and tibia. Accuracy was evaluated by measuring the mineral content of bone powder capsules (within the range of rat vertebrae BMD), under 0.5–3 cm water to mimic variations in soft tissue thickness. The bone powder capsule mineral content was highly correlated with chemically determined hydroxyapatite content (r = 0.999). In vivo reproducibility was evaluated by calculating the coefficient of variation (CV = 100 × SD/mean) of four to six BMD measurements, each time with repositioning, in seven rats (220–500 g body weight). CV was 1.36 ± 0.32% (x ± SD) for lumbar spine, 0.66 ± 0.50% for proximal tail, and 1.12 ± 0.45% for tibia. The ability to detect BMD changes was investigated by measuring BMD before and every 4 weeks after ovariectomy (OVX) in 270 g rats, pair fed during the whole experiment. Compared with sham-operated control animals, a highly significant difference in lumbar spine BMD was observed 4 weeks after OVX, which reached a maximum by 8 weeks and remained stable thereafter. At the level of the proximal tibia, the difference was maximal 4 weeks after OVX. In contrast, proximal tail BMD was only slightly affected by OVX (p &lt; 0.05). In conclusion, BMD measurements by noninvasive DEXA is feasible in small experimental animals. It seems to be accurate and precise, allowing the detection of BMD changes over short-term periods, particularly at lumbar and peripheral sites with high trabecular bone content. This technique should be useful for the development of therapies aimed at increasing bone mass.
Rat osteoclasts adhere to a wide range of rgd (arg-gly-asp) peptide-containing proteins, including the bone sialoproteins and fibronectin, via a β3 integrin
Authors: Helfrich Miep H. , Nesbitt Stephen A. , Dorey Elaine L. , Horton Michael A. 
Published: February 2010

Abstract
The ligand binding ability of rat osteoclast adhesion receptors was investigated in an attachment assay using osteoclasts disaggregated from bone. Osteoclasts adhered well to the Arg-Gly-Asp (RGD)-containing proteins osteopontin (bone sialoprotein I) and BSP (bone sialoprotein II), vitronectin, fibrinogen, von Willebrand factor, and fibronectin. Osteoclasts also adhered, but less strongly, to type I collagen. No attachment of osteoclasts was observed to thrombospondin, tenascin, laminin, or a range of non-RGD-containing bone proteins and proteins from other sources. The attachment of osteoclasts to all ligands was abolished in the presence of GRGDSP peptide, indicating the involvement of the RGD cell binding sequence in ligand binding. Attachment of osteoclasts to all substrates, with the exception of type I collagen, was also strongly inhibited by the addition of monoclonal antibody F11 to the β3 integrin subunit, indicating that a β3 integrin, probably the vitronectin receptor, was involved. Attachment to type I collagen was blocked by EDTA chelation of divalent cations and was not significantly affected by anti-β3 or anti-β1 antibodies; when taken with the inhibition by RGD peptide, this suggests the involvement of various receptors, possibly including nonintegrin collagen receptors, in the binding of osteoclasts to this protein. These results define the wide range of ligands for extracellular matrix receptors in osteoclasts in vitro. It remains to be established which of these proteins are important in osteoclast adhesion and osteoclastic bone resorption in vivo.
Performance of dual-energy X-ray absorptiometry in evaluating bone, lean body mass, and fat in pediatric subjects
Authors: Chan Gary M. 
Published: February 2010

Abstract
We studied the performance of the dual-energy x-ray absorptiometry method in evaluating bone mineral, fat, and lean soft tissue mass. This method was accurate in quantifying known small amounts of calcium, lard, and lean tissue mass. It was also accurate in evaluating small animal ashed bones, fat, and muscle mass. The analytic sensitivity of the method was 40 mg for calcium, 180 mg for fat, and 270 mg for lean tissue mass. The method was highly correlated to the single-photon absorptiometry method in measuring bone mineral content at the radius bone in 32 children, r = 0.998. There was a difference between the two methods in older children. Long-term precision for a small bone phantom was 2.0%. Total-body, lumbar, and radial bone scans were performed on 14 newborn infants whose gestational ages ranged from 28 to 41 weeks. Both total-body bone mineral and fat mass increased with gestational age and weight. The infant's total-body calcium was also associated with length and lumbar and radial bone densities. The lumbar bone density was associated with birth weight, gestational age, length, body mass index, body fat, and radial bone density. Male infant's lumbar bone density to total-body calcium ratio was higher than female infant's lumbar bone density ratio. Dual-energy x-ray absorptiometry may be used in pediatrics with high accuracy, sensitivity, and precision.