ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    An FT-IR microscopic investigation of the effects of tissue preservation on bone (1992)
    Springer
    Calcified tissue international 51 (1992), S. 72-77 
    Details
    ISSN: 1432-0827
    Keywords: Fixation ; FT-IR microscopy ; Infrared spectroscopy ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Fourier transform infrared microscopy is a powerful tool for the characterization of mineral and protein in histologic sections of bone. This study was concerned with determining whether techniques used to preserve these tissties and to prepare them for sectioning had an effect on spectral properties. The υ1, υ3 phosphate bands in the 900–1200 cm-1 spectral region were used to evaluate the structure of the apatitic mineral in fresh-frozen, ethanol-fixed, and formalin-fixed 35-day-old rat femurs; fresh-frozen and formalin-fixed 20-day-old fetal rat femurs; ground 35-day-old rat diaphyseal bone samples; and formalin-fixed, methacrylate-embedded ground diaphyseal bone. The crystallinity (crystal size and perfection) of the bone apatite was assessed by a curve-fitting analysis of the υ1, υ3 phosphate bands. Results indicate that ethanol or formalin fixation of the 35-day-old intact rat femur, and formalin fixation and embedding of the ground rat bone do not significantly alter the crystallinity of the apatite. However, formalin fixation of the fetal rat bone did alter the structure of the apatite mineral phase. In addition, evaluation of protein secondary structure in the 35-day-old rat femur from the Amide I and Amide II vibrations near 1650 and 1550 cm-1, respectively, revealed that protein conformation was altered by ethanol fixation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296221
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The inhibitory effect of cartilage proteoglycans on hydroxyapatite growth (1984)
    Springer
    Calcified tissue international 36 (1984), S. 285-290 
    Details
    ISSN: 1432-0827
    Keywords: Proteoglycans ; Chondroitin 4-sulfate ; Neutral dextran ; Hydroxyapatite growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The calcification of connective tissues, including cartilage, is under the control of many interacting systems. Proteoglycans are thought to retard the deposition of hydroxyapatite crystals, and modification of the proteoglycans presumably facilitates mineralization in those tissues that are actively calcifying. The mechanism underlying these regulations remains speculative. This study investigates this question by comparing the inhibitory effectiveness of several macromolecules at neutral pH and approximately physiological ionic strengths. Inhibitors tested include bovine nasal proteoglycan monomer A1D1D1 and aggregate-containing A1 fractions, glycosaminoglycan chains (chondroitin 4-sulfate), and neutral dextran (as an uncharged analog). Hydroxyapatite growth was assessed either by measuring the time-dependent decreases in solution calcium and phosphate concentrations, or by determining utilization of hydroxyl ion in a pH-Stat. All species studied inhibit hydroxyapatite growth, and the extent of inhibition for each class is concentration-dependent. The proteoglycan aggregate-containing A1 fraction is more effective than the proteoglycan monomer at the same concentration, and the proteoglycan monomer is more effective than chondroitin 4-sulfate. Neutral dextran inhibits hydroxyapatite growth less effectively than proteoglycans. These results suggest that inhibition of hydroxyapatite growth by proteoglycans critically depends on both status (aggregate, monomer, etc.) and hydrodynamic size of this macromolecule, supporting the hypothesis that modification of proteoglycansin vivo functions to modulate the effectiveness of proteoglycans as a hydroxyapatite growth inhibitor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02405332
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    FT-IR microscopic mappings of early mineralization in chick limb bud mesenchymal cell cultures (1992)
    Springer
    Calcified tissue international 51 (1992), S. 443-448 
    Details
    ISSN: 1432-0827
    Keywords: Hydroxyapatite ; Mineralization ; Cartilage calcification ; FTIR ; Infrared spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Chick limb bud mesenchymal cells differentiate into chondrocytes and form a cartilaginous matrix in culture. In this study, the mineral formed in different areas within cultures supplemented with 4 mM inorganic phosphate, or 2.5, 5.0, and 10 mM β-glycerophosphate (βGP), was characterized by Fourier-transform infrared (FT-IR) microscopy. The relative mineral-to-matrix ratios, and distribution of crystal sizes at specific locations throughout the matrix were measured from day 14 to day 30. The only mineral phase detected was a poorly crystalline apatite. Cultures receiving 4 mM inorganic phosphate had smaller crystals which were less randomly distributed around the cartilage nodules than those in the βGP-treated cultures. βGP-induced mineral consisted of larger, more perfect apatite crystals. In cultures receiving 5 or 10 mM βGP, the relative mineral-to-matrix ratios (calculated from the integrated intensities of the phosphate and amide I bands, respectively) were higher than in the cultures with 4mM inorganic phosphate or in the in vivo calcified chick cartilage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296678
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Osteopontin and Related Phosphorylated Sialoproteins: Effects on Mineralization (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 760 (1995), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1995.tb44635.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Hydroxyapatite formation in a dynamic collagen gel system: effects of type I collagen, lipids, and proteoglycans (1989)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 93 (1989), S. 1628-1633 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100341a086
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Conversion of amorphous calcium phosphate to microcrystalline hydroxyapatite. A pH-dependent, solution-mediated, solid-solid conversion (1973)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 77 (1973), S. 2313-2317 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100638a011
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The role of synthetic and bone extracted Ca-phospholipid-PO4 complexes in hydroxyapatite formation (1977)
    Springer
    Calcified tissue international 23 (1977), S. 251-258 
    Details
    ISSN: 1432-0827
    Keywords: Hard tissue mineralization ; Phospholipids ; Ca-phospholipid-PO4 complex ; Hydroxyapatite formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The calcium-phospholipid-phosphate (Ca-PL-PO4) complex isolated from young bone has been shown to initiate hydroxyapatite formation from a metastable calcium phosphate solution. The action of the complex was compared to that of the acidic phospholipids: phosphatidyl serine, phosphatidyl inositol and phosphatidic acid. These phospholipids first remove calcium, and a small amount of phosphate from the metastable solution forming a material similar to the complex isolated from bone, and then form hydroxyapatite. The rate of hydroxyapatite proliferation, once phosphatidyl serine and phosphatidyl inositol are converted to Ca-PL-PO4 complexes, is the same as the rate observed for comparable weights of the complex isolated from bone. It is suggested that the complex isolated from bone was formed in a manner similar to the complexes in our in vitro experiments. Finally, our evidence supports the possiblity that a similar complex is responsible for the initial mineralization in matrix vesicles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02012794
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Phosphate modulation of calcium transport by a calcium-phospholipid-phosphate complex of calcifying tissues (1984)
    Springer
    Calcified tissue international 36 (1984), S. 317-319 
    Details
    ISSN: 1432-0827
    Keywords: Ca-PS-P complex ; Ionophoretic activity ; Ca2+ ; Ca2+ transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The ionophoretic activities of a stable Ca-PS-Pi complex were examined in a three-compartment lipid-aqueous phase transport system. It was found that the complex transported Ca2+ at a slower rate than free PS. Analysis of the transport process, using an equilibrium partitioning model, revealed that Ca2+ binding to the complex was the rate-limiting step. This inhibition was overcome by the addition of exogeneous Pi. It was concluded that the complex acted as an ionophore and that the presence of coordinated Ca and P atoms facilitated Pi modulation of Ca2+ transport.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02405336
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Adenosine 5′-triphosphate promotes mineralization in differentiating chick limb-bud mesenchymal cell cultures (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 28 (1994), S. 492-504 
    Details
    ISSN: 1059-910X
    Keywords: Calcification ; Hydroxyapatite ; Matrix synthesis ; FT-IR microscopy ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: When chick limb-bud mesenchymal cells are plated in micromass culture, they differentiate to form a mineralizable cartilage matrix. Previous studies have demonstrated that, when the total inorganic phosphate concentration of the medium is adjusted to 3-4 mM by adding inorganic phosphate to the basal medium, the mineralized matrix formed resembles that of chick calcified cartilage in ovo. When the high-energy phosphates adenosine 5′-triphosphate (ATP) or creatine phosphate are used as supplements in place of inorganic phosphate, the mineralized matrix as analyzed by electron microscopy and Fourier transform infrared microscopy is also similar to that in ovo. This is in marked contrast to the mineralized matrix formed in the presence of 2.5-5 mM β-glycerophosphate, where mineral deposition is random and mineral crystal sizes in general are larger. This is also in contrast to the known ability of ATP to inhibit mineral deposition in solution in the absence of cells.In the differentiating mesenchymal cell culture system, ATP does not alter the rate of cell proliferation (DNA content), the rate of matrix synthesis (3H-leucine uptake), the mean crystallite length, or the rate of mineral deposition (45Ca uptake) when contrasted with cultures supplemented with inorganic phosphate. However, ATP does increase the mineral to matrix ratio, especially around the edge of the culture, where a type I collagen matrix is present. It is suggested that ATP promotes mineral deposition by providing a high-energy phosphate source, which may be used to phosphorylate extracellular matrix proteins and to regulate calcium flux through cell membranes. © 1994 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070280605
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Two-dimensional infrared correlation spectroscopy of synthetic and biological apatites (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Biospectroscopy 2 (1996), S. 353-364 
    Details
    ISSN: 1075-4261
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Two-dimensional (2D) infrared (IR) correlation spectroscopy was used to monitor the ν1, ν3 phosphate contour (900-1200 cm-1) of maturing poorly crystalline hydroxyapatite in synthetic (synthesized at constant and variable pH) and biological (calcified turkey leg tendon) systems. The 2D IR plots of the mineral prepared at variable pH exhibit peaks at 961, 999, 1018, 1036, 1095, 1126, and 1150 cm-1. The peaks at 961, 999, and 1095 cm-1 represent vibrations of PO3-4 in an apatitic/stoichiometric environment of poorly crystalline HA, while those at 1018, 1036, and 1126 cm-1 arise from PO3-4 in a nonstoichiometric/acid phosphate environment of poorly crystalline HA. The 2D IR analysis suggests that the intensities of peaks associated with PO3-4 in a nonstoichiometric/acid phosphate environment decrease as the reaction progresses. The 2D IR plots of the mineral formed at constant pH showed only bands characteristic of PO3-4 in a stoichiometric/acid phosphate environment. Analysis of the 2D IR plots of the mineral from calcified turkey leg tendon reveals peaks at 1019, 1039, 1075, 1126, and 1147 cm-1. The peaks at 1019, 1039, and 1126 cm-1 are characteristic of PO3-4 in a nonstoichiometric/acid phosphate environment of poorly crystalline HA, while the band at 1075 cm-1 is characteristic of PO3-4 in an apatitic/stoichiometric environment of poorly crystalline HA. Thus, the in vitro experiment in which the mineral is formed at variable pH is a better model of the mineral phase in calcified turkey leg tendon. In addition, the asynchronous plots from both the synthetic and biological minerals revealed those peaks which were noncorrelated. Also, this method of data analysis provided enhanced resolution of the highly overlapped ν1, ν3 phosphate contour commonly seen in Fourier transform-IR spectra of calcified tissue. © 1996 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...