ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Bone
  • Springer  (31)
  • American Association for the Advancement of Science
  • 2010-2014
  • 2005-2009
  • 1980-1984  (31)
  • 1965-1969
  • 1925-1929
  • 1983  (14)
  • 1981  (17)
Collection
Publisher
  • Springer  (31)
  • American Association for the Advancement of Science
  • Wiley-Blackwell  (1)
Years
  • 2010-2014
  • 2005-2009
  • 1980-1984  (31)
  • 1965-1969
  • 1925-1929
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 239-242 
    ISSN: 1432-0827
    Keywords: Bone ; Magnetic field ; IR light ; Light absorption constant ; Efficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Enhancement of photovoltage has been found in bone and its two major constituents when placed in a magnetic field in standard Hall geometry. Infrared light has been used for carrier excitation. From data obtained in this manner, values for the light absorption constant, extinction constant, mass absorption constant, and efficiency have been estimated. All these parameters increase with the increase of magnetic field. A possible explanation for the observed phenomena is presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0827
    Keywords: Vitamin D ; Vitamin D deficiency ; Cartilage ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary To test the importance of 24-hydroxylation of vitamin D3 on bone mineralization, rat pups born to vitamin D-deficient females were given either 25-hydroxyvitamin D3 or 24,24-difluoro-25-hydroxyvitamin D3 for 16 days beginning at the time of weaning. Following such treatment analysis of blood samples revealed no detectable 24R,25-(OH)2D3 and 1,25-(OH)2D3 in the rats given the difluoro compound while revealing the expected 24,24-difluoro-25-hydroxyvitamin D3 and 24,24-difluoro-1,25-dihydroxyvitamin D3. The rats given 25-hydroxyvitamin D3 had the expected levels of 25-hydroxyvitamin D3, 24,25-dihydroxyvitamin D3, and 1,25-dihydroxyvitamin D3. Following sacrifice at day 17, postweaning bone mineralization and modeling were studied in long bones using histological methods. Bones taken from vitamin D-deficient rats at the beginning and end of the experimental period had lesions typical of rickets. These included wide growth plates, excessive amounts of osteoid, and metaphyseal fibrosis. Following treatment with either 25-hydroxyvitamin D3 or 24,24-difluoro-25-hydroxyvitamin D3, bone mineralization returned to normal. Growth plate widths and the amount of osteoid on bone surfaces were both substantially reduced and to a similar degree in both treatment groups. Normal cartilage core formation and trabecularization of the metaphyseal primary spongiosa were also restored to a similar degree in both groups. In effect, no difference was observed in any bone parameter studied between the 25-hydroxyvitamin D3- and the 24,24-difluoro-25-hydroxyvitamin D3-treated animals. These results provide strong evidence that 24-hydroxylation of the vitamin D molecule plays little or no role in the modeling and mineralization of bone.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 655-661 
    ISSN: 1432-0827
    Keywords: 1,25-Dihydroxyvitamin D3 ; 25-Hydroxyvitamin D3 ; 24,25-Dihydroxyvitamin D3 ; Receptors ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The hormonal metabolite of vitamin D3, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], exerts its biological effects by binding to a cytosolic receptor protein. Such a protein has been demonstrated in vitamin D3 target organs including fetal rat calvariae and more recently in rat osteogenic sarcoma cells. In this study we have compared the binding of 25-hydroxyvitamin D3 [25(OH)D3] and 24,25-dihydroxyvitamin D3 [24,25(OH)2D3] to that of 1,25-(OH)2D3 in fetal rat calvariae and osteogenic sarcoma (OS) cells. Sucrose density sedimentation, DNA-cellulose chromatography, and intracellular uptake studies have been employed to evaluate these interactions. In cytosol preparations from calvariae, [3H]-1,25(OH)2D3 bound to a 3.3S macromolecule and to a much greater extent to a 5.8S macromolecule while both [3H]25(OH)D3 and [3H]24,25(OH)2D3 bound to the 5.8S macromolecule. By incubating intact calvariae and OS cells with labeled metabolites and thus establishing binding intracellularly prior to cell disruption, we have found that the 3.3S protein which has high specificity for 1,25(OH)2D3 occurs inside the cells; the 5.8S protein, however, does not occur inside the cells but is generated after cell disruption. The [3H]-1,25(OH)2D3-receptor complex adsorbed to DNA-cellulose and was eluted from this affinity resin at 0.28M KCl. In contrast, [3H]25(OH)D3 and [3H]-24,25(OH)2D3 binding activity did not adsorb to DNA-cellulose. We conclude that, in contrast to the 3.3S protein, the 5.8S macromolecule does not fulfill receptor criteria but is rather generated by the experimental manipulation of the bone cells. Our data suggest that the vitamin D3 actions on bone are mediated only via the 3.3S receptor, and hence quantitative but not qualitative differences of the effects of the various metabolites are feasible.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0827
    Keywords: Vitamin D ; Bone ; Osteoblasts ; Receptors ; 1,25-dihydroxyvitamin D3
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Thaw-mount autoradiographic studies after injection of3H-1,25-D3 were conducted on 18-and 20-day-old rat fetuses. In maxillary bones, ribs, and tibia, nuclear concentration of radioactivity was found in osteoprogenitor cells and osteoblasts. Osteocytes and chondrocytes in epiphyseal plates were either unlabeled or weakly labeled. In competition experiments, nuclear concentration of radioactivity was blocked by the injection of a high dose of nonradioactive 1,25-D3 prior to the administration of the labeled hormone, but not by a similar dose of nonradioactive 25-D3. The results are interpreted as indicating that osteoprogenitor cells and osteoblasts are target cells for the direct action of 1,25-D3 on fetal bone.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0827
    Keywords: Vitamin D ; Vitamin D deficiency ; Bone ; Cartilage ; Bone development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The role of vitamin D in early skeletal development was studied by measuring serum calcium and phosphorus, osseous tissue quantity and mineralization, and endochondral bone elongation in rat fetuses and pups from vitamin D-replete and vitamin D-deficient mothers. At the 20th day of pregnancy there was a slight, yet significant, increase in the amount of osteoid on trabecular bone surfaces in fetuses from vitamin D-deficient mothers. The fetal bones otherwise appeared normal in spite of severe skeletal changes in the vitamin D-deficient mothers. After parturition, the importance of vitamin D in skeletal development becomes progressively more obvious. Serum calcium levels were slightly, yet significantly, lower in vitamin D-deficient than in vitamin D-replete pups and these levels continued to fall in the vitamin D-deficient pups through lactation and after weaning. At 3 days postpartum, there was a small, yet significant, increase in the amount of osteoid on bone surfaces of the vitamin D-deficient pups. The relative amounts of osteoid in the vitamin D-deficient pups continued to increase through lactation and after weaning when compared with vitamin D-replete pups. By the 14th day of lactation and at later periods, there were significant reductions in metaphyseal mineralized tissues in the vitamin D-deficient pups when compared with the vitamin D-replete pups. At weaning and after weaning, there were substantial increases in growth plate thickness and decreases in longitudinal bone growth in the vitamin D-deficient pups when compared with the vitamin D-replete pups. The results from this study indicate that vitamin D does not appear to play a major role in fetal skeletal development. However, after birth, vitamin D becomes progressively more important with age for normal bone development, mineralization, and endochondral growth.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 35 (1983), S. 481-485 
    ISSN: 1432-0827
    Keywords: Chemotaxis ; Bone ; Osteoblasts ; Bone proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary When demineralized bone matrix powder is implanted subcutaneously in the rat, the early responses involve the appearance and proliferation of mesenchymal cells at the site of implantation, followed by cartilage and bone formation. The ability of cells to migrate to the implant suggests that chemotaxis may be a critical event in this process. Therefore, using the modified Boyden chamber assay, we tested extracts of demineralized bone matrix for chemotactic activity. We have identified and partially purified, on molecular sieve chromatography, a heat labile and trypsin-sensitive protein (Mr=60,000–70,000) that is a potent chemoattractant for mouse calvaria, osteoblast-like cells (MMB-1), but not for monocytes (putative osteoclast precursors). These findings suggest that chemotactic protein(s) have a significant role in the recruitment of osteoprogenitor cells to a site of bone repair.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 35 (1983), S. 762-766 
    ISSN: 1432-0827
    Keywords: Enamel ; Maturation cycles ; Tetracycline ; Dentine ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Uptake of tetracycline by enamel in the short-term was studied at an advanced stage of crown formation and after completion of crown formation in deciduous molars in the cat. Both secretory phase enamel and bands of postsecretory, maturation phase enamel labeled rapidly. The pattern of labeling mimicked that seen in the continuously growing, rootless incisor teeth of the rat, with narrow doublets fusing to form narrow bands with wide unlabeled intervals in the short term. This is a physiological demonstration which indicates that cyclical activity and changes may occurin vivo during the maturation phase of amelogenesis in rooted teeth. It is also noted that dentine did not, and that some circumscribed patches of bone did label in the same animals in the same time interval. Short-term tetracycline labels are lost following conventional histological processing, but are retained after freeze-drying or air-drying.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 35 (1983), S. 148-152 
    ISSN: 1432-0827
    Keywords: Bone ; Computed tomography ; Densitometry ; Osteoporosis ; Osteomalacia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The linear attenuation coefficient (μ in cm1) of trabecular bone was modeled for different conditions of bone and marrow composition in order to assess their influence on computed tomography (CT) quantitation. A large relative change (10% of TBV at 15% TBV) of bone concentration resulted in small changes of μ: 2.3% at 60 keV, 3.4% at 44 keV, 5.2% at 29 keV. Relative changes of trabecular bone volume (TBV) on the order of 3% could be detectedin vivo by CT were it not for errors of relocation and for compositional influences on accuracy. The μ (and density) depended critically not only on amounts of bone substance and marrow but on their compositions. Normal variation in the composition of bone substance produced an uncertainty in μ equivalent to 0.5 to 1% TBV. Increases of yellow marrow produced a decrease of μ which could be mistaken for a decrease of bone concentration. The biological variation (90% confidence limit) of marrow composition gives an uncertainty at 15% TBV of about 2.4% TBV at 60 keV, 1.7% at 44 keV, and 1.3% at 29 keV. These correspond to relative uncertainities of 16, 11, and 9% respectively. These factors help explain the large accuracy errors (30%) observed in all studies of trabecular bone where single-energy CT was used. Marrow composition also can affect precision of bone measurement. Systematic shifts of red and yellow marrow could mask biological changes such as those occurring with aging or treatment.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 111-117 
    ISSN: 1432-0827
    Keywords: Calcium-deficient hydroxyapatite ; Amorphous calcium phosphate ; Bone ; Radial distribution function ; Carbonate apatite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary When amorphous calcium phosphate (ACP) was transformed to crystalline hydroxyapatite (HA) in a series of aqueous slurry concentrations ranging from low to high, the higher slurry concentrations produced more Ca-deficient HA as measured by Ca/P ratio and heat-produced pyrophosphate. We feel that the excess solution phosphate produced in the higher slurry transformations results in lower Ca/P ratio HA. It has been suggested that an ACP is the precursor to bone apatite. Regulation of the in vivo ACP slurry concentration could then control the stoichiometry and, therefore, the metabolic activity of bone apatite. X-ray radial distribution function (RDF) analyses showed that CO 3 2− substitution in HA creates far greater structural distortions than do Ca deficiencies. The latter, however, do produce small, but observable, structural distortions when compared to stoichiometric HA. It now seems clear that the RDF of bone apatite can be modeled by a synthetic, Ca-deficient, CO 3 2− -containing HA.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-0827
    Keywords: Phosphoprotein ; Bone ; 31P-NMR ; Phosphoserine ; Phosphothreonine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Fractionation of the EDTA-soluble, noncollagenous proteins of the organic matrix of chicken bone by Sephadex G-100 molecular sieving has revealed that the majority of the organic phosphorus is present in two fractions, from one of which a homogeneous phosphoprotein has been isolated. The purified phosphoprotein has an apparent molecular weight of 12,000 and contains bothO-phosphoserine andO-phosphothreonine.31P-NMR spectroscopy demonstrates that all of the organic phosphorus exists in the form of phosphomonoesters which have an average pK2 of 6.8. The phosphoprotein is highly acidic due to its high content of dicarboxylic acids in addition to the presence of organic phosphorus. The characteristic amino acid composition of the phosphoprotein establishes its noncollagenous nature and highlights the differences among bone, dentin, and enamel phosphoproteins. The absence ofγ-carboxyglutamic acid distinguishes it from osteocalcin, the noncollagenousγ-carboxyglutamic acid-containing peptide of bone matrix.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 455-457 
    ISSN: 1432-0827
    Keywords: Bone ; Osteoporosis ; Diabetes mellitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The bone mineral status of fifty-one children with diabetes mellitus was studied by single photon absorptiometry. The mean bone mineral content was 13% below values predicted by age, sex, height, and weight. Those children whose diabetes was one year or less in duration were as osteopenic as those whose diabetes was of longer duration. The demineralized children received a higher daily insulin dose than the others. No association was noted between the degree of skeletal demineralization and sex, statural growth, renal function, and serum calcium and phosphorus. No significant changes in bone mineral content were noted longitudinally.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1432-0827
    Keywords: Bone ; Calcium metabolism ; Whole-body counting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A whole-body counter was used to measure the retention and distribution of radioactivity along the longitudinal axis of the body during 10 days after the intravenous injection of 50 µCi of47Ca. These data and the simultaneous measurements of the serum specific activity allowed us to calculate, by the Bauer-Carlsson-Lindquist (BCL) formulas generalized by Marshall, the calcium accretion rate and exchangeable pool in 7 areas: skull, thorax, pelvis, thighs, knees, legs, and ankles and feet. For the whole body, the accretion rate was 336±115 mg/24 h, and the exchangeable pool 5668±1221 mg, in 26 subjects without bone disease. Both parameters were significantly correlated with body height; the exchangeable pool was significantly higher in men than in women. The accretion rate and exchangeable pool expressed on a basis of bone content varied widely from one area to another, reflecting the ratio of spongy to compact bone: the thorax, pelvis, and arms, which contain 49% of the skeletal mass, accounted for 57% of the total accretion rate and 53% of the exchangeable pool; the skull, 18% of the skeletal mass, accounted for 14% of the accretion and 11% of the pool.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1432-0827
    Keywords: Dentin ; Bone ; Apposition rate ; Parathyroid hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The dose-dependency of the effects of parathyroid hormone (PTH) on bone and dentin apposition after both intermittent and continuous administration of the hormone was investigated. The purpose was to compare the sensitivity of these two mineralizing tissues to parathyroid hormone and to provide additional information regarding the direct effect of PTH on mineralized tissue formation. Adult rats were thyroparathyroidectomized and 5 groups of 4 or 5 rats each were given daily subcutaneous injections with different doses of bovine parathyroid hormone. Five more groups of 4 rats each were administered equivalent dosages by means of a continuous infusion pump implanted subcutaneously. An additional group of 4 rats served as controls. All animals were labeled with tetracycline injected on days 7, 9, and 11. The animals were killed on day 12 and blood samples were collected for serum calcium determination. The lower metaphysis of the femur and the left and right mandibles were dissected out, and undecalcified sections of plastic-embedded tissues were prepared. The distances between the three tetracycline bands were measured to determine the amount of bone or dentin formation. Results indicated that both dentin and bone apposition increased with higher dosages of hormone. No overall effect of the method of administration was evident. For both methods, bone apposition showed a more pronounced increase over the control levels than dentin apposition. This suggests that, although both osteoblasts and odontoblasts appear to respond directly to PTH, differences do exist in the magnitude and dose-dependency of the response. No causal relationship was found between increases in serum calcium levels and either bone or dentin apposition at the lower dose levels.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 35 (1983), S. 728-731 
    ISSN: 1432-0827
    Keywords: Bone ; Bioelectricity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The origin of the bioelectric potentials in unstressed living bones is still an open question. Blood-flow in vessels, stationary potentials on peripheral nerves, muscle injury potentials, and viability of bone cells are claimed to be possible sites of origin of the electric potentials recorded on bone surface. The present data show that the topographic quantitative distribution of tetracycline labeling at sequential levels of rabbit tibia and the distribution pattern of the bioelectric potentials in this bone are significantly superimposable. This coincidence of bone formation rates and bioelectric potentials seems to support the view that the latter are in some way linked with the laying down of new bone.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1432-0827
    Keywords: Bone ; Osteosarcoma ; Matrix vesicles ; Alkaline phosphatase ; Aminopeptidase ; Naphthylamidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Extracellular matrix vesicles from bovine fetal alveolar bone and from a dog osteosarcoma were isolated by differential centrifugation and then fractionated on a discontinuous sucrose density gradient. The fractions were examined by electron microscopy and were analyzed for protein, alkaline phosphatase, aminotripeptidase, and four different β-naphthylamidase activities. The low-density peak of enzyme activities was shown by electron microscopy to be much more homogeneous than the crude matrix vesicle fraction. Two major peaks of protein and enzyme activities were present, one in the high and one in the low density layers. There was good correlation between the activities of alkaline phosphatase and the various peptidases in the fractions from the sucrose density gradient. These results indicate a coexistence of peptidase and alkaline phosphatase in matrix vesicles. On the other hand, there was generally no correlation between the peptidase and alkaline phosphatase activities in vesicular specimens from bovine liver obtained in the same way. Most of the peptidase activity and about half of the alkaline phosphatase activity were solubilized from bone matrix vesicles by detergents. The extracted alkaline phosphatase and alanyl β-naphthylamidase activities were separated from each other on a DEAE-cellulose column.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 57-69 
    ISSN: 1432-0827
    Keywords: Thallium ; Chondrodystrophy ; Cartilage ; Bone ; Matrix
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Using the transmission electron microscope, we sought to describe the morphology of thallium sulfate-induced chondrodystrophy in chick embryos. There was cell death and degeneration in all zones of growth cartilage, but the cells and matrix of the hypertrophic zone were the most severely affected. Ultrastructural changes of the hypertrophic chondrocytes consisted of alteration of the cytoplasmic contents and of the intercellular matrix; the cell membrane was smooth and without cytoplasmic extensions. The cytoplasm was filled with dilated rough endoplasmic reticulum, vacuoles of varying sizes and contents, and lipidlike bodies with electron-dense granules; mineral crystals, collagen, and degenerating mitochondria were present. The matrix showed only spotty calcification and a reduced number of dense bodies, vesicles, and granules. The cells appeared to have failed to exteriorize cell products across the plasmalemma. Failure to exteriorize cell products and to form cytoplasmic processes reduced the number of potential nucleation sites for calcification. The ultrastructure of osteocytes was much less affected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 89-99 
    ISSN: 1432-0827
    Keywords: Soluble proteoglycans ; Resistant proteoglycans ; Collagen ; Bone ; Cartilage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Soluble proteoglycans (SPG) were extracted from bovine (BCC) and human (HCC) costal cartilages by the dissociative method using 4 M guanidinium chloride (GuHCl). Proteoglycans which are resistant to extraction (RPG) were obtained following collagenase digestion or hydroxylamine treatment of the cartilage residues. Similarly, SPG were extracted from bovine metaphyseal and cortical bone using EDTA. The RPG were extracted from the bones using hydroxylamine. Density gradient fractionation under dissociative conditions of cartilage SPG and RPG followed by chromatography on Sepharose 2B revealed that A1D1 RPG are smaller than the SPG. SPG reacted with either collagenase or hydroxylamine are also smaller than the parent SPG. A1D1 fractions obtained from BCC-SPG and RPG or from mixtures of SPG and acid-soluble collagen are free of hydroxyproline. Hydroxyproline is not completely separated from HCC-RPG. Density gradient fractionation of bone proteoglycans and Sepharose chromatography of the A1 and A1D1 fractions showed that those obtained from metaphysis are larger than those from cortical bone. This was attributed to the presence of calcified cartilage in metaphyseal bone. The A1D1 fractions of the metaphyseal proteoglycans seemed to undergo self-association since this fraction is larger than the A1 fraction from which it is derived. Cortical bone proteoglycans do not behave similarly. Density gradient purification under dissociative conditions failed to separate hydroxyproline from the proteoglycans obtained from bone. It is hypothesized that in bone proteoglycans and collagen might be linked.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 567-574 
    ISSN: 1432-0827
    Keywords: Bone ; Femur ; Age ; Mineral ; Apatite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary It has previously been observed that after the third decade of life the tensile strength of bone decreases faster than its density [1], indicating that some microstructural change occurs in bone with advancing age. In order to try to elucidate this observation, the orientation and particle size of the mineral phase of bone have been studied with respect to age. Samples were taken from femora varying in age from 13 to 97 years. The results show that the degree of preferred orientation does not vary with age after the first decade of life. However, the percentage of small particles increased up to the fourth decade of life and thereafter decreased, a pattern of change similar to that observed for bone strength. It would seem to indicate that an increase in mineral particle size is a factor that contributes to the loss of bone strength and that an increased percentage of large particles in the later years of life could, along with osteoporosis, help to explain the increased fragility in the bones of the elderly.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1432-0827
    Keywords: Bone ; Mineral ; Crystallinity ; Maturation ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The crystallinity of bone mineral at different stages of maturation has been measured by quantitative X-ray diffraction methods. Crystallinity measurements were made on tibial middiaphyses from 17-day embryonic chicks, newlyformed periosteal bone from embryonic chicks, and density-fractionated bone from post-hatch chickens from 5 weeks to 2 years of age. For a given animal age and degree of mineralization, crystallinity increases with animal age, indicating that changes in bone mineral occur even after mineralization is complete or nearly complete.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 1432-0827
    Keywords: ADP ; Bisphosphonate ; Bone ; Resorption ; Formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The effects of 1.5–2 years oral administration of disodium (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (APD) on bone metabolism were studied in male and female rats. APD was mixed in the food at levels of 500, 2,000 and 10,000 ppm. A dose-dependent increase in metaphyseal bone was found, indicative of continued inhibition of bone and cartilage resorption. APD did not affect mineralization of bone and cartilage, primary bone formation, or periosteal apposition. A short-term metabolic balance study was performed to compare the effects of oral with subcutaneous APD. Absorption of APD was in the order of 0.2%. Oral APD increased absorption of phosphate, probably by complexation of calcium with APD. The excess absorbed phosphate increased phosphaturia and decreased urinary calcium.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 369-374 
    ISSN: 1432-0827
    Keywords: Histomorphometry ; Bone ; Reproducibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary To study bone histomorphometry reproducibility in normal subjects, we performed during orthopedic surgery bone biopsies in 16 post-menopausal women. Each woman had four bone biopsies, two at the usual site in the iliac crest, one on the left and one on the right side, and two other biopsies just behind the usual site, one at each side. We performed measurements of trabecular bone volume, relative osteoid volume, osteoid surfaces, osteoclastic resorption surfaces and calcification front. The average values of the 16 patients were compared, on the one hand, two by two, by a student test, and on the other hand, by a variance analysis. By these two methods the results showed no significant difference between the average values of the 16 patients at each location for any of the histomorphometric parameters studied. However, there was a location variation which was estimated by the intra-individual variation for a given patient. On the other hand, we calculated from the variance analysis the location variance for a group of 10 to 100 patients. In any case all the parameters had a location variation which was high for osteoclastic resorption surfaces and relative osteoid volume when expressed in % of the absolute value of these parameters. The variation of the trabecular bone volume was 0–46. 15% (95% confident limit interval) in a single patient and the hypothetical value of the location variation was 41.6% for a group of 10 patients and 13.0% for a group of 100 patients.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 441-444 
    ISSN: 1432-0827
    Keywords: Bone ; Diffusion ; H2O ; Ions ; Vitamin D ; Diphosphonate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The rates of diffusion of small ions and neutral molecules through isolated calvaria have been determined. Compared with data published on self-diffusion and diffusion through cartilage, H2O, 3-O-methylglucose, lactate, sulfate, and methylamine diffuse at approximately 2/3 the expected rate. Diffusion of H2O and sulfate was unaffected by the administration of the diphosphonate 1-hydroxyethane-1,1-diphosphonate (EHDP), although phosphate fluxes are markedly diminished. Diffusion of water was nearly doubled by vitamin D deficiency. A 1-week treatment with 1,25(OH)2D3 had no effect on H2O diffusion while returning calcium influx to normal. It is concluded that bone matrix permits a flow of small neutral and ionized molecules nearly comparable to that in cartilage. When changes in calcium and phosphate influx are observed, they can be ascribed to the exchange properties of bone mineral and not to changes in matrix permeability.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 499-504 
    ISSN: 1432-0827
    Keywords: Bone ; Collagen ; Density
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The density of a bovine cortical bone matrix sample was found in water, several ethanol-water solutions, and in the dried state. Previously the density of the same mineralized bone was found fresh and when desiccated. The volume in each state was estimated from the dimensional changes axially, tangentially, and radially. Confirmation was found by determining the density of dried specimens upon immersion in xylene. The amount of imbibed xylene provided an estimate of the free pore volume in the dried matrix. The volume fraction of the solid constituent, S, in the wet matrix was found to be 0.57, from which the density of S in various solutions was calculated. Density of wet matrix in 0.15 M saline: 1.180 g/cc; for dried matrix, 1.246 g/cc. Density of wet S in saline: 1.33 g/cc; for dried S, 1.42 g/cc, which matches published values for collagen molecules. Dimensional changes between wet and dried state of matrix match published values for artificially cross-linked rat tail tendon fibers. Axially: 1.04, by area: 2.27; by volume: 2.62. Estimate of intrafibrillar volume, assuming 80% of mineral is within fibrils: 0.73 cc/g dry collagen.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 631-639 
    ISSN: 1432-0827
    Keywords: Bone ; Osteopenia ; Noninvasive monitoring
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Radiological techniques were utilized for monitoring progressive changes in compact bone in the tibia of monkeys during experimentally induced osteopenia. Bone mass loss in the tibia during restraint was evaluated from radiographs, from bone mineral analysis, and from images reconstructed from gamma ray computerized tomography. The losses during 6 months of restraint tended to occur predominantly in the proximal tibia and were characterized by subperiosteal bone loss, intracortical striations, and scalloped endosteal surfaces. Bone mineral content in the cross section of the tibia declined 17–21%. Tomography demonstrated endosteal widening and reduced mineral content per unit of thickness of cortical bone. In 6 months of recovery, the mineral content of the proximal tibia remained depressed. Effects of the dynamic environment on local-regional changes in various skeletal areas are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 33 (1981), S. 35-39 
    ISSN: 1432-0827
    Keywords: Copper ; Resorption ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary An investigation of the role of copper in bone metabolism was undertaken. Explanted calvaria from 6-day-old mice were grown for 48 h in medium with and without the addition of copper sulfate. Active resorption was found to be significantly inhibited in the presence of copper sulfate concentrations of 10−6M and above. Copper sulfate concentrations of 10−5M and above inhibited hydroxyproline, protein, and DNA synthesis. Lower concentrations were ineffective. The effect of 5 × 10−6M copper sulfate on resorption was reversible. Several other compounds were tested for similar effects and at 5 × 10−6M were found to inhibit bone resorption in the order: copper sulfate 〉 brown gold chloride 〉 sodium aurothiomalate 〉 zinc sulfate 〉 sodium sulfate. The copper sulfate effect was twice that of sodium aurothiomalate, and sodium sulfate was not significantly inhibitory. The results suggest that the high serum copper levels associated with rheumatoid arthritis may reflect the activity of a hypothetical control mechanism of bone resorption. In the diseased state this would act to restore the normal rate of bone resorption.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 233 (1983), S. 689-691 
    ISSN: 1432-0878
    Keywords: Fluoride ; Progeny ; Bone ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Femurs of weanling rats from third-pregnancy litters of dams given 150 ppm fluoride in the drinking water were examined by light- and scanning-electron microscopy. Under the conditions of the experimental procedure, no pathological changes were seen in the femurs as a result of maternal ingestion of fluoride. These results indicate that the amount of fluoride crossing the placenta and mammary gland was insufficient to produce significant morphological changes in the bones of 3-week-old rats.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Annals of biomedical engineering 11 (1983), S. 263-295 
    ISSN: 1573-9686
    Keywords: Bone ; Mechanical bone properties ; Functional adaptation of bone tissue ; Mathematical models of Hooke's law
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract The properties of bone tissue as a material and bones as the structural elements of the skeleton are reviewed and summarized. The first half of this work describes bone tissue microstructure, the stress-strain relations, and the strength and fracture of bone. The second and slightly larger half concerns the adaptation of living bone tissue to its load environment. Some observations and experiments of bone remodeling due to applied stress are described and continuum models for this process are formulated. An example of bone remodeling leading to shape changes in the bone is described as well as an example of bone remodeling leading to changes in the bulk density of the bone tissue.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 214 (1981), S. 583-591 
    ISSN: 1432-0878
    Keywords: Fucose ; Bone ; Parathyroid hormone ; Adenosine cyclic monophosphate ; Colchicine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Radioautographic and scintillation counting procedures were used to examine the effect of parathyroid hormone (PTH), dibutyryl cyclic-AMP (DB-cAMP), and colchicine on the incorporation of 3H-fucose into macromolecular material in organ cultures of bone. Radioautography demonstrated 3H-fucose incorporation into bone cells, with the heaviest uptake occurring in osteoclasts. A minimal incorporation occurred in pre-osteoblasts and osteoblasts of the osteogenic periosteum, and in fibroblasts of the fibrous periosteum. PTH appeared to produce a heavier label in association with osteoclasts while decreasing the limited labeling associated with cells of the osteogenic and fibrous periosteum. DB-cAMP and colchicine both markedly reduced the labeling associated with osteoclasts, while the minimal labeling of other bone cells remained. By contrast, scintillation counting results indicated that PTH had little or no effect on 3H-fucose incorporation, while DB-cAMP and colchicine considerably reduced the amount of labeled macromolecular material. The incorporation of 3H-fucose into glycoproteins and the role of glycoproteins are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 221 (1981), S. 421-430 
    ISSN: 1432-0878
    Keywords: Fluoride ; Bone ; Mineralization ; Resorption ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The femurs from rats given 120 ppm fluoride in their drinking water for 4 weeks were examined with histological, histochemical, and radiographic methods. Blood removed from the rats prior to sacrifice was analyzed for calcium, phosphorus, and alkaline phosphatase. Results of this study indicated that the ingestion of fluoride produced wide osteoid seams on the periosteal surface of the femoral diaphysis within 4 weeks. The increase in osteoid appeared to be due to an increase in the number of osteoid-producing cells (osteoblasts) along with a subsequent delay in the mineralization of this tissue. The metabolic activity of osteoblasts did not appear to be affected since the intracellular production of acid and alkaline phosphatase was not inhibited. However, due to the high concentration of fluoride ingested, abnormal collagen deposition and a change in bone mineral may have combined to cause a delay in osteoid mineralization. Mineralization was also delayed in the distal femoral epiphyseal plate resulting in an increase in the number of hypertrophied cells. Resorption of metaphyseal trabecular bone, presumably formed prior to fluoride administration, was increased causing a reduction in the amount of trabeculae extending into the shaft of the femur. Concurrent with these changes in bone, the serum levels of calcium, phosphorus, and alkaline phosphatase remained within normal ranges.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    Medical & biological engineering & computing 21 (1983), S. 509-510 
    ISSN: 1741-0444
    Keywords: Bone ; Bone growth ; Magnetic fields ; Orthopaedics ; Pulsed magnetic field therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    Medical & biological engineering & computing 19 (1981), S. 49-54 
    ISSN: 1741-0444
    Keywords: Bone ; Biopotentials ; Impedance ; Loss factor ; Stimulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Some electrical parameters such as biopotentials, impedance, charge, power availability, loss factor and corresponding Q values have been measured in unstressedin vivo bone in adult rabbits. Measurements were performed with stainless steel electrodes implanted in the bones (tibia and femur). By placing a variable resistance across any two electrodes, the power available from the source was also obtained. Intact bone was subjected to d.c. stimulation by passing a constant current between the extreme electrodes and the potential profile and the charge retention were measured all along the affected medium. It is hoped that these data obtained will establish some quantitative relationship between the bone electrical behaviour and the electret phenomena.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...