Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Effects of parathyroid hormone on the osteoclastic pool, bone resorption and formation in rat alveolar bone (1978)
    Springer
    Calcified tissue international 26 (1978), S. 23-28 
    Details
    ISSN: 1432-0827
    Keywords: Parathyroidectomy ; Parathyroid hormone ; Osteoclasts ; Bone remodeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The osteoclast number and its relation to parathyroid hormone have been studied in rat alveolar bone by quantitative histology and fluorescent labeling. The osteoclast number decreases 60 h after parathyroidectomy and remains constant for the next 132 h. Parathyroid hormone administration to parathyroidectomized animals 96 h after the operation induces an increase in osteoclast number within 12 h to some-what above those of control animals. The elevated osteoclast counts remain constant for 60 h then rapidly fall over the next 24 h to the level seen in untreated parathyroidectomized animals. As determined by fluorescent labeling, normal alveolar bone resorption and formation were disturbed by parathyroidectomy, such that significant bone formation occurred for only 6 days after surgery, after which a quiescent state followed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013229
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Isolation of specific bone cell types by free-flow electrophoresis (1979)
    Springer
    Calcified tissue international 27 (1979), S. 263-268 
    Details
    ISSN: 1432-0827
    Keywords: Bone cells ; Separation ; Free-flow electrophoresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The bone cells and fibroblasts from fetal rat calvaria can be isolated by collagenase digestion of the collagen matrix and separated into specific cell types by free-flow electrophoresis. The method involves injection of a specially prepared suspension of cells into a stream of buffer across which is maintained an electric field of 60 V/cm. The fetal bone cell types are differentially deflected toward the anode where they can be collected. Free-flow electrophoresis of this heterogenous cell preparation yields three distinguishable peaks which can be identified by morphologic, morphometric, and enzymatic characteristics. All three cell peaks have greater than 95% viability as judged by trypan blue exclusion and will grow to confluent monolayers in culture. The data indicate that these cell peaks may be comprised of osteoclasts and/or preosteoclasts, osteoblasts and/or preosteoblasts, and fibroblasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441195
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Cellular kinetics of the bone remodeling sequence in the rat (1982)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 202 (1982), S. 445-451 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The kinetics of the bone remodeling sequence in the rat has been studied using a system in which well-synchronized remodeling units were induced along the periosteum of rat mandibles. Remodeling of the periosteal surface of the mandibles was induced according to Tran Van (1979) by extraction of the opposing row of teeth; namely, the right maxillary molars were extracted under light ether anesthesia, therefore allowing the right mandibular molars to egress; this, in turn, induced a wave of remodeling activity on the buccal side of the periosteal surface of the alveolar bone. The quantification of the different cellular activities involved in bone remodeling has been performed up to 16 days after induction. This allowed us to demonstrate the sequential activity of the different cell types involved in bone remodeling, to study the cellular kinetics of this sequence of events, and to directly measure the duration of each phase of the bone remodeling sequence. A single wave of osteoclasts appeared 3 days after induction, reached a peak at 4-5 days, and then decreased sharply. This was followed by a single wave of mononuclear cells (Baron et al., 1980) within remodeling sites during the reversal phase; they appeared 4 days after induction, reached a peak by day 7, and then decreased sharply. This reversal activity was then followed by osteoblasts forming new bone on top of a reversal cement line in the remodeling sites, starting 6 days after induction and increasing until the end of the experiment. In addition, the synchronization of the system used in this study allowed direct measurement of the duration of the successive steps of the remodeling sequence. The directly measured values have then been compared to previous data calculated from other systems.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092020403
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Histomorphometry and autoradiography of cultured fetal rat long bones (1982)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 204 (1982), S. 105-112 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The behavior of fetal rat long bones cultured in vitro according to Raisz's technique (1969) was studied by histomorphometry and autoradiography for a period of four days. The changes were recorded daily both on the trabecular and cortical bone by measuring the bone volume, the number of osteoclasts, and the number of nuclei per osteoclast. Radioactive calcium release was measured and compared to the changes in bone volume and in the number of osteoclasts. An autoradiographic study, using 3H-proline and 3H-thymidine in flash labeling in the medium and 3H-thymidine in follow-up labeling after one injection in vivo was performed to evaluate the bone formation, the cellular proliferation rate and cell differentiation. After four days in culture, an increase in total calcified bone volume was observed which correlatd with changes in the trabecular bone. No significant changes were recorded in the cortical bone. The results showed a good maintenance of the resorption and formation phenomena through an active process of cellular multiplication and differentiation. Undifferentiated cells were labeled in flash label and osteoblast, osteocyte and some osteoclast nuclei were labeled in follow-up studies.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092040203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Evidence of sequential remodeling in rat trabecular bone: Morphology, dynamic histomorphometry, and changes during skeletal maturation (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 208 (1984), S. 137-145 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The occurrence of a sequential bone remodeling activity, similar to what is observed in human bone, is demonstrated in rat trabecular bone at the level of the secondary spongiosa. A complete dynamic histomorphometric analysis of the remodeling activity, using undecalcified sections and double fluorescent labels, has consequently been performed in young adults (220 g, 8 weeks old) and in more mature animals (320 g, 12 weeks old). The results showed that, despite a similar trabecular bone volume, younger animals had a five times higher bone formation rate and five times more osteoclasts than more mature animals. The higher bone formation rate was due in part to a threefold higher extent of double-labeled trabecular bone surface and in part to a 1.5-fold faster mineralization rate. These results therefore demonstrate a marked slowing down of bone turnover during skeletal maturation in the rat. The values obtained in this study have been compared with measurements made in other parts of the skeleton in the same species (Vignery and Baron 1978, 1980b; Tran Van et al., 1982a) or in humans. This comparison indicated that 12-week-old rats had a turnover rate very similar to values observed in iliac crest trabecular bone in adult humans. The rat is therefore a good experimental animal for the study of trabecular bone remodeling but since large variations occur during skeletal maturation, care should be taken in the selection of an age group relevant to the type of questions being asked.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092080114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Dynamic histomorphometry of alveolar bone remodeling in the adult rat (1980)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 196 (1980), S. 191-200 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Alveolar bone normally undergoes remodeling on one side of the socket and modeling on the opposite side as the tooth migrates at a rate of 6.7 μm per day. Periodontal ligament width, however, remains constant. Because of this very high turnover rate, this bone is a good model to study bone modeling and remodeling activities. This study was undertaken in order to measure the different cellular events occurring during tooth migration along the alveolar bone of the rat. The histomorphometric measurements performed on this model permitted us to calculate the duration of each phase of the remodeling cycle, i.e., resorption lasts about 1.5 days and reversal about 3.5 days. Since the duration of the forming phase is about 1 day (Guyomard and Baron, ′74), the total duration of each remodeling cycle is about 6 days. This time is very short compared to 60-120 days in adult human trabecular bone. Additionally, in this model each osteoclast resorbs 2-4 times its own volume of bone per day. Based on this knowledge, it will be possible to measure accurately the effects of experimental conditions on bone cells and bone remodeling in this rat alveolar bone model.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091960210
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    An electron-microscopic study of the bone-remodeling sequence in the rat (1982)
    Springer
    Cell & tissue research 225 (1982), S. 283-292 
    Details
    ISSN: 1432-0878
    Keywords: Bone remodeling ; Osteoclast ; Osteoblast ; Mononuclear-phagocytes ; Osteoclast precursors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A detailed chronological electron-microscopic study of the bone remodeling sequence has been performed in the rat based on a previously described model (Tran Van et al. 1982) in which the remodeling activity is synchronized. This allowed the observation of the cellular and extracellular events during the bone remodeling process, including the activation of the sequential process and the reversal phase, intermediate between osteoclastic resorption and osteoblastic formation. Most important is the fact that throughout the whole process cells with the morphological characteristics of mononuclear phagocytes have been observed in proximity or in contact with the bone surface and/or the various bone cells. Coated pits (receptor-mediated endocytosis) are frequently observed in close apposition to bone spicules and gap junctions are frequent between the cells. These observations suggest that, besides being likely candidates as osteoclast precursors, mononuclear phagocytes may play an important role in bone remodeling.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214682
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Macrophages express functional receptors for calcitonin-gene-related peptide (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 149 (1991), S. 301-306 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The present study was designed to investigate whether non-activated macrophages express calcitonin (CT) or calcitonin-gene-related peptide (CGRP) receptors. To this end, we first analyzed whether CT and CGRP induce a cAMP accumulation in macrophages. Macrophages were treated for 2 min with increasing concentrations of either CT or CGRP in the presence or absence of IBMX. A dose-dependent cAMP accumulation was measured in response to CGRP with a half-maximal effect attained with 1 nM CGRP. CT failed at all doses to induce an accumulation of cAMP. The effects of CT and CGRP on the activation of the Na-H exchanger were next assessed by spectrofluorometry by using the pH-sensitive dye 2,7 biscarboxyethyl-5(6)-carboxyfluorescein (BCECF). Steadystate pHi of macrophages in a 7.4, HCO3-free solution (HEPES-buffered) was 7.04 ± 0.08 (n = 22). pHi recovery following an NH4+/NH3 acid load was inhibited by the removal of Na+ or by the addition of the amiloride analog EIPA; therefore recovery is dependent on Na-H exchange activity. CT had no effect on steady-state pHi but CGRP increased pHi in a dose-dependent fashion (10-12 to 10-6M). The pHi change induced by CGRP was due to the stimulation of the Na-H exchanger as CGRP enhanced the rate of recovery (dpHi/dt) from an acid load from 45.3 to 77.2 μMs-1 (n = 8, P 〈 0.002) and was completely blocked by EIPA. These data indicate that CGRP both enhances the activity of the Na-H exchanger and increases intracellular cAMP, thus demonstrating that macrophages express functional CGRP receptors.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041490217
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...