Abstract：
:The peptide hormone calcitonin is a potent inhibitor of osteoclastic resorption, but it is unstable and poorly absorbed following oral administration. Conjugates of salmon calcitonin covalently linked to low-molecular-weight amphiphilic polymers show improved stability and absorption. The purpose of this study was to investigate the biological activity of these conjugates in vitro using rat osteoclasts and HEK-293 cells transfected with the C1a isoform of the calcitonin receptor. Salmon calcitonin or its conjugates (10 pM-10 nM) caused rapid arrest of osteoclast membrane ruffling and subsequent retraction. The same amphiphilic polymer attached to an unrelated protein had no effect on osteoclast morphology or motility. Since calcitonin-induced retraction of osteoclasts is thought to be mediated by Ca2+ signaling, we investigated the effects of calcitonin and its conjugates on cytosolic free Ca2+ concentration ([Ca24]i). In HEK-293 cells transfected with the calcitonin receptor, these agents induced transient elevations of [Ca2+]i. However, the rise of [Ca2+]i in HEK-293 cells occurred at concentrations 100-1000-fold higher than those required to elicit osteoclast retraction. To investigate the role of Ca2+ in osteoclast retraction, we preloaded cells with BAPTA to buffer changes in [Ca2+]i. BAPTA decreased the initial rate of calcitonin-induced osteoclast retraction, but it did not affect the degree of retraction 2-3 hours following calcitonin, indicating that retraction is mediated primarily by Ca(2+)-independent processes. We conclude that calcitonin conjugates cause osteoclast retraction and [Ca2+]i signaling in a manner similar to that elicited by calcitonin. Thus, orally bioavailable calcitonin conjugates show potential for use as antiresorptive agents.
journal_name
Calcif Tissue Intjournal_title
Calcified tissue internationalauthors
Komarova SV,Shum JB,Paige LA,Sims SM,Dixon SJdoi
10.1007/s00223-002-1051-4subject
Has Abstractpub_date
2003-09-01 00:00:00pages
265-73issue
3eissn
0171-967Xissn
1432-0827journal_volume
73pub_type
杂志文章abstract：:The purpose of this study was to use the concept of metastable equilibrium solubility (MES) to describe the anomalous solubility behavior of carbonated apatite (CAP) in the presence of solution strontium. A CAP sample (4.8 wt% CO(3), synthesized at 70 degrees C) was prepared by precipitation. Baseline MES distribution...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-002-0035-8
更新日期：2004-01-01 00:00:00
abstract：:Aging and sex hormones related changes lead to inflammatory and oxidant conditions, which are involved in the pathogenesis of osteoporosis. Recent studies have suggested that polyphenols may exert a protective effect in such conditions. We assessed the effect of phloridzin (Phlo), a flavonoid exclusively found in appl...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-005-0060-5
更新日期：2005-11-01 00:00:00
abstract：:It is generally accepted that bone formation is depressed during corticosteroid treatment, but the effects of glucocorticoids on bone resorption are less well characterized. We have investigated the effects of short-term treatment with high-dose oral glucocorticoids on biochemical markers of bone turnover in 20 consec...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s002239900482
更新日期：1998-07-01 00:00:00
abstract：:Noncarious cervical lesions have a multifactorial etiology. Mechanical stress has been identified as one of the factors, but little evidence exists for its cause-effect relationship. This study was conducted at three different pH levels to observe the surface loss on dentin beams under tension and compression. Bovine ...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-005-0271-9
更新日期：2006-12-01 00:00:00
abstract：:In vitro models of osteogenesis are essential for investigating bone biology and the effects of pharmaceutical, chemical, and physical cues on bone formation. Osteogenesis takes place in a complex three-dimensional (3D) environment with cells from both mesenchymal and hematopoietic origins. Existing in vitro models of...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-011-9467-3
更新日期：2011-05-01 00:00:00
abstract：:There is increasing evidence that 1,25 dihydroxyvitamin D3 acts directly to differentiate and activate cells of mononuclear phagocyte lineage (MNP). However, it seems possible that in bone marrow this hormone may modulate the differentiation of MNP via the factor elaborated by the stromal cells or the macrophages. We ...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/BF02556592
更新日期：1986-01-01 00:00:00
abstract：:X-linked hypophosphatemia (XLH) is a rare, inheritable disorder manifesting as rickets in children and osteomalacia in adults. While conventional medical treatment with oral phosphate and alfacalcidol is recommended in childhood, it is undecided whether adults should continue therapy. The aim of this 6-year prospectiv...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-017-0363-3
更新日期：2018-03-01 00:00:00
abstract：:Measurements of broadband ultrasonic attenuation (BUA) represent an established means of skeletal status assessment in osteoporosis. Today, the skeletal site that is the most widely used clinically is the calcaneus (heel bone). However, we hypothesized that fracture risk predictions could be improved if ultrasound mea...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-004-0216-8
更新日期：2004-11-01 00:00:00
abstract：:Raman spectroscopy has been used to demonstrate, for the first time, that calcium mineralization in the core of the major lateral teeth of the chiton Acanthopleura echinata takes place as an ordered process, with crystalline carbonated apatite being the first mineral deposited. Deposition begins at the top of the toot...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s002230001156
更新日期：2000-11-01 00:00:00
abstract：:The binding of prostaglandin E2 (PGE2) to bone cells was studied to provide direct evidence for the existence of specific receptors in bone. Bone cells were isolated by collagenase digestion of fetal and newborn rat calvaria. Isolated cells were incubated with 3H-PGE2 and collected on Millipore filters. Specific bindi...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/BF02405038
更新日期：1983-01-01 00:00:00
abstract：:Data have accumulated to show that various types of collagen crosslinking are implicated in the health of individuals, as well as in a number of disease states, such as osteoporosis, diabetes mellitus, chronic kidney disease, inflammatory bowel disease, or in conditions of mild hyperhomocysteinemia, or when glucocorti...
journal_title：Calcified tissue international
pub_type： 杂志文章,评审
doi：10.1007/s00223-015-9985-5
更新日期：2015-09-01 00:00:00
abstract：:Seventy-two postmenopausal osteoporotic women having more than one nontraumatic vertebral crush fracture were studied. Thirty-six of them, aged 68.8 +/- 1.2 years (18 +/- 4 YSM-years since menopause), were treated with 100 IU/day of salmon calcitonin i.m. plus 500 mg of elemental calcium for 10 days each month. The re...
journal_title：Calcified tissue international
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1007/BF00298606
更新日期：1995-03-01 00:00:00
abstract：:Data on the association between dietary vitamin K intake and fracture risk are limited among Chinese. This study examined such an association in community-dwelling elderly in Hong Kong. We present data from 2,944 subjects (1,605 men, 1,339 women) who participated in a prospective cohort study. Baseline dietary intakes...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-012-9586-5
更新日期：2012-05-01 00:00:00
abstract：:The gut microbiota (GM) is the whole of commensal, symbiotic, and pathogenic microorganisms living in our intestine. The GM-host interactions contribute to the maturation of the host immune system, modulating its systemic response. It is well documented that GM can interact with non-enteral cells such as immune cells,...
journal_title：Calcified tissue international
pub_type： 杂志文章,评审
doi：10.1007/s00223-017-0331-y
更新日期：2018-04-01 00:00:00
abstract：:Regular physical activity (PA) is associated with reduced risk of the development and progression of musculoskeletal, metabolic and vascular disease. However, PA declines with age and this can contribute to multiple adverse outcomes. The aims of this study were to describe the relationship between accelerometer-determ...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-018-0413-5
更新日期：2018-09-01 00:00:00
abstract：:To clarify the mechanisms underlying shockwave-induced osteogenesis, we applied shockwave to rat femoral shafts from the ventral side. We assessed bone mineral content (BMC) and bone mineral density (BMD), and analyzed the spatial and temporal gene expression for pro-alpha1 (I) collagen (COL1A1), pro-alpha1 (II) colla...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-003-0043-3
更新日期：2004-02-01 00:00:00
abstract：:Vit-D-Dependent calcium binding protein and parvalbumin have both been detected in ameloblasts and calcified cartilage by immunohistochemical techniques. These two Ca2+ binding proteins may play a crucial role in the local accumulation of Ca2+ ions during the process of mineralization. The mechanisms underlying the de...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/BF02405306
更新日期：1984-01-01 00:00:00
abstract：:Conventional glucocorticoids exert a negative influence on calcium balance, and long-term treatment with these agents leads to osteopenia. Deflazacort is an oxazoline derivative of prednisolone with documented calcium-sparing properties when compared to prednisone on a weight basis. The purpose of the present study wa...
journal_title：Calcified tissue international
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1007/BF02556669
更新日期：1987-12-01 00:00:00
abstract：:The goals of internal fixation are an accurate reduction and stable fixation in the presence of adequate bony vascularity. This can be achieved by a variety of means including plate fixation. A certain amount of periosteal stripping is necessary for proper open reduction of a fracture and for proper plate application....
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s002239900080
更新日期：1996-07-01 00:00:00
abstract：:The recent advancement of high resolution magnetic resonance imaging has opened up new avenues for the determination of structural characteristics of the trabecular network, which may significantly improve the diagnosis of osteoporosis. An analysis of the calcaneus in healthy women has shown similar age-related change...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s002230001168
更新日期：2001-03-01 00:00:00
abstract：:Prior exposure to PTH markedly decreased the responsiveness of isolated, cultured bone cells to the stimulatory effect of the hormone on cyclic AMP formation. This process of desensitization developed within 30 min, persisted during prolonged incubation of the cells in PTH-free medium, and could not be attributed to e...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/BF02408528
更新日期：1980-01-01 00:00:00
abstract：:1,25(OH)2D3 was found to regulate its own receptor levels via an increase in corresponding mRNA levels in human osteoblast-like osteosarcoma cells (MG-63). In addition, exposure of the cells for 24h to dexamethasone, estradiol, retinoic acid, or triiodothyronine resulted in a dose-dependent accumulation of hVDR mRNA. ...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/BF02555101
更新日期：1991-01-01 00:00:00
abstract：:Patients put at bedrest for medical reasons lose 1-2% of spinal bone mineral per week. Losses of this magnitude during even short-term space flights of a few months would pose a serious limitation and require countermeasures. The spinal bone mineral (L2-L4) was determined in 6 healthy males (precision = 2%) before and...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/BF02555226
更新日期：1987-11-01 00:00:00
abstract：:Paget's disease of bone (PDB) is a chronic and focal bone disorder, characterized by increased osteoclast-mediated bone resorption and a subsequent compensatory increase in bone formation, resulting in a disorganized mosaic of woven and lamellar bone at one or more affected skeletal sites. As a result, bone pain, noti...
journal_title：Calcified tissue international
pub_type： 杂志文章,评审
doi：10.1007/s00223-019-00522-3
更新日期：2019-05-01 00:00:00
abstract：:The effect of the configuration of porous cylindrical hydroxyapatite (HA) scaffold and laminin preparation of the scaffold on bone formation was estimated. HA scaffolds with a hollow center of 2 or 4 mm in diameter and those without a hollow center were used. The scaffolds were immersed in laminin solution or in cultu...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-008-9157-y
更新日期：2008-08-01 00:00:00
abstract：:We compared the effects of four vitamin D metabolites, 1 alpha,25 dihydroxy vitamin D3 (1 alpha,25(OH)2D3), 1 alpha hydroxy vitamin D3 (1 alpha OH D3), 25 hydroxy vitamin D3 (25 OH D3), and 24R,25 dihydroxy vitamin D (24R,25(OH)sD3) on resorption and collagen synthesis in fetal rat bone maintained in organ culture. Re...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/BF02408532
更新日期：1980-01-01 00:00:00
abstract：:Dual photon absorptiometry (DPA) is currently the most widely used method for noninvasive bone mineral density (BMD) measurement of the axial skeleton. Dual energy X-ray absorptiometry (DEXA) is a recently developed technique that uses an X-ray tube as a photon source; it has demonstrated several significant advantage...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/BF02556250
更新日期：1991-11-01 00:00:00
abstract：:The wedges of the mid-diaphyseal osteotomies carried out to correct the femoral and/or tibial native deformity in type III osteogenesis imperfecta (OI III) were used to study the remodeling patterns and lamellar organization at the level of the major deformity. Histology and scanning electron microscopy (SEM) morpholo...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/s00223-013-9771-1
更新日期：2013-11-01 00:00:00
abstract：:The absorption kinetics of intranasal salmon calcitonin were assessed in 4 normal subjects and 9 patients with Klinefelter's syndrome. After administration, absorption occurred within 5 minutes. There was a highly significant correlation between the amount administered and the amount absorbed (r = -0.83, P less than 0...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/BF02556097
更新日期：1990-02-01 00:00:00
abstract：:Bone labeling, histochemical, and fine structural studies were performed in order to clarify the effects of ipriflavone (IP) on rat bone tissue in vivo and in vitro. Labeling experiments showed a slight increase in bone formation during 3 days' administration. It was also noted that many osteoclasts detached from the ...
journal_title：Calcified tissue international
pub_type： 杂志文章
doi：10.1007/BF02180245
更新日期：1992-01-01 00:00:00
