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  • Collagen
  • Springer  (11)
  • American Meteorological Society
  • Blackwell Publishing Ltd
  • Cambridge University Press
  • Institute of Physics
  • Springer Nature
  • 1990-1994
  • 1980-1984  (6)
  • 1965-1969  (5)
  • 1983  (6)
  • 1968  (5)
Collection
Publisher
  • Springer  (11)
  • American Meteorological Society
  • Blackwell Publishing Ltd
  • Cambridge University Press
  • Institute of Physics
  • +
Years
  • 1990-1994
  • 1980-1984  (6)
  • 1965-1969  (5)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 35 (1983), S. 401-405 
    ISSN: 1432-0827
    Keywords: Collagen ; Crosslinks ; Dentin ; Human ; Bovine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The hydroxypyridinium crosslinks of collagen are believed to derive from reducible, divalent crosslinks. To study this concept further, both types of crosslink were quantified as a function of age in dentin, a tissue thought to have minimal collagen turnover. Human (5, 15, 28 and 56 years) and bovine (fetal and adult) root dentin was analyzed by a procedure that measures both hydroxypyridinium and reducible crosslinks on the amino acid analyzer. In human dentin, hydroxypyridinium crosslinks increased with age and became the predominant crosslinks as the two reducible residues, dehydrodihydroxylysinonorleucine and dehydrohydroxylsinonorleucine, diminished. Similarly in adult bovine dentin, hydroxypyridinium residues were sixfold more concentrated than in fetal bovine dentin. Borohydride treatment of tissue did not influence the measured content of hydroxypyridinium residues. The analyses also ruled out natural reduction as a stabilizing reaction for the divalent, reducible crosslinks. Though hydroxypyridinium residues became the major aldehyde-mediated crosslinks of adult dentin collagen, significant levels of reducible crosslinks remain throughout the tooth's adult life.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 35 (1983), S. 542-548 
    ISSN: 1432-0827
    Keywords: Osteoblasts ; Epidermal growth factor ; Alkaline phosphatase ; Collagen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The effect of epidermal growth factor (EGF) on clone MC3T3-El cells that have osteoblastic activity was examined by phase-contrast microscopy and electron microscopy; hydroxyproline content, collagen synthesis, collagen pattern, and alkaline phosphatase (ALP) activity were also determined. We found that EGF (0.4 ng/ml) transformed the cells from their normal polygonal shape to a spindle-like morphology by 8 h. This hormone also caused dose-related suppression of hydroxyproline content and ALP activity which was detectable 2 days and 1 day, respectively, after EGF addition. Indomethacin did not affect hydroxyproline content and ALP activity, suggesting that the effect of EGF on the cells may not be mediated by prostaglandins. Epidermal growth factor at concentrations of 2 to 50 ng/ml significantly decreased collagen synthesis in the cells, whereas protein synthesis was stimulated. Electron microscopy demonstrated that collagen fiber formation was also reduced by EGF; an immature type of fibril was observed compared with the typical cross-striated one in the controls. Moreover, the hormone treatment also resulted in the appearance of type III collagen in addition to the type I already present in the cells. These suppressive effects of EGF on MC3T3-El cellsin vitro suggest that this hormone may be involved in bone remodellingin vivo as well.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 35 (1983), S. 43-47 
    ISSN: 1432-0827
    Keywords: Noncollagenous protein ; Dentin ; Aging ; Racemization ; Collagen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Highly phosphorylated noncollagenous proteins (NCP) with molecular weights of ∼70–100,000 daltons have been purified from rat and bovine dentin. Efforts to isolate phosphoprotein from human teeth have not yielded consistent results, and failures have been attributed to proteolysis due to preparative techniques. Diagenetic reactions affecting metabolically stable proteinsin vivo also can interfere in protein purification. Racemization is one of the reactions known to take place in human dentin. EDTA extraction of dentin from an age-graded series of human teeth has yielded an EDTA-soluble NCP fraction having an aspartic acid racemization rate 3 X that in unfractionated dentin and 8 X the rate in EDTA-insoluble protein. D-Aspartic acid is accumulating in EDTA-S protein at a rate of 0.22% yr−1. For humans, more than 13% of the aspartyl residues in NCP will be the D-enantiomer by 60 years of age. While racemization presents no problem for shorter lived mammals, such as rats, it could be partly responsible for purification difficulties with human dentin.
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  • 4
    ISSN: 1432-041X
    Keywords: Collagen ; Fibronectin ; Laminin ; Skin ; Scale morphogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Collagen types I and III were purified from the skin of 3-or 7-week-old chickens, collagen type IV from bovine skin or EHS mouse tumour, fibronectin from human serum, and laminin from EHS mouse tumour. Antibodies were produced in rabbits or sheep, and used in indirect immunofluorescence on frozen sections of 9-to 16-day-old normal or mutant (scaleless) chick-embryo foot skin. In normal scale-forming skin and inscaleless skin, the distribution of anti-laminin and anti-type IV collagen label was uniform along the dermal-epidermal junction and showed no stage-related variations, except for fluorescent granules located in the dermis of early scale rudiments. By contrast, in normal scale-forming skin, the density of anti-types I and III label decreased in the dermis within scale rudiments, whereas it gradually increased in interscale skin. Conversely, anti-fibronectin label accumulated at a higher density within scale rudiments than in interscale skin. In the dermis of thescaleless mutant, anti-types I and III label and antifibronectin label were distributed evenly: the density of anti-collagen label increased with age, while that of antifibronectin decreased and almost completely vanished in 16-day-old skin, except around blood vessels. The microheterogeneous distribution of some extracellular matrix components, namely interstitial collagen types I and III and fibronectin, is interpreted as part of the morphogenetic message that the dermis is known to transmit to the epidermis during the formation of scales. The even distribution of these components in mutantscaleless skin is in agreement with this view. Basement membrane constituents laminin and type-IV collagen do not appear to be part of the dermal morphogenetic message.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 2 (1968), S. 343-352 
    ISSN: 1432-0827
    Keywords: Nucleation ; Mineralization ; Bone ; Collagen ; Apatite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Nous avons utilisé de la collagène d'os de mounton et de tendons de queues de rats et des cristaux d'apatite pour étudier dans un système modèle la catalysation de la nucléation et la déposition de minéral dans un tampon métastabile. La collagène d'os de mouton se trouvait être un bon catalysateur, tandis que des expériences antérieures ont démontré que la collagène de tendons de queues de rats était un catalysateur très faible. Le phase rapide de la déposition de l'apatite dans la collagène se termine aussitôt que le contenu du minéral a attaint au plus 50 à 60 pour cent, bien que la supersaturation du tampon est encore bien èlevée. Les résultats montrent que dans un tel système modèle la quantité du depôt minéral est réglée par des facteurs semblables à ceux qui opèrent pendant la calcification biologique.
    Abstract: Zusammenfassung Kollagen aus Schafsknochen und Rattenschwanzsehnen und Apatitkeime wurden verwendet in einem Modell-System zur Untersuchung der katalytischen Nukleation und der Fällung von Mineral in einem metastabilen Calciumphosphatpuffer. Kollagen aus Schafsknochen war ein guter Katalysator für die Nukleation, während in früheren Versuchen sich herausstellte, daß Rattenschwanzkollagen ein ganz schlechter Katalysator ist. Die schnelle Phase der Apatitfällung im Kollagen war beendet, wenn der Mineralgehalt bis zu 50–60% angestiegen war, obwohl der Puffer noch stark übersättigt war. Die Resultate weisen daraufhin, daß die Menge des gefällten Minerals in einem solchen Modell-System von ähnlichen Faktoren reguliert wird wie die biologische Verkalkung.
    Notes: Abstract Sheep bone collagen, rat tail tendon collagen and apatite seeds were used in a model system to study nucleation catalysis and mineral deposition in a metastable calcification buffer. Sheep bone collagen was shown to be a good nucleation catalyst, while earlier experiments have shown that rat tail tendon collagen was a very poor catalyst. The rapid phase of apatite deposition in the collagen was terminated as soon as a mineral content of not more than 50–60 per cent was reached, although the buffer was still highly supersaturated. The results suggest that the amount of mineral deposited in such a model system is regulated by factors similar to those operating in biological calcification.
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  • 6
    ISSN: 1432-0827
    Keywords: Calcification ; Glycosaminoglycan ; Glycoprotein ; Collagen ; Acid phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Glycosaminoglycans (GAGs) and glycoproteins are essential components for osteogenesis. We have examined rat osteoblasts, osteoid, transitional zone, and fully calcified bone matrix, utilizing Spicer's high-iron diaminethiocarbohydrazide-silver protein (HID-TCH-SP) method for sulfated glycoconjugates and Thiéry's periodate-TCH-SP (PA-TCH-SP) method for vicinal glycol-containing glycoconjugates. HID-TCH-SP stained cytoplasmic granules of osteoblasts. Stain deposits in the extracellular matrix were observed in decreasing amounts in osteoid, the transitional zone, and fully calcified bone matrix. Enzyme digestion with testicular hyaluronidase removed most HID-TCH-SP stain deposits. PA-TCH-SP staining was observed with increasing intensity in rough endoplasmic reticulum, Golgi saccules, and cytoplasmic granules. Collagen fibrils in osteoid were weakly stained with PA-TCH-SP, and their staining appeared even weaker in fully calcified bone matrix. In contrast, collagen fibrils in calcified cartilage stained intensely with the PA-TCH-SP method. Focal circular profiles (0.1–0.5µm in diameter), which lacked collagen fibrils but reacted moderately with PA-TCH-SP, were frequently seen in the transitional zone and fully calcified bone matrix, but were only occasionally present in osteoid. The presence of testicular hyaluronidase-resistant GAG and acid phosphatase in these focal areas suggests that they represent sites of GAG degradation. The eventual loss of HID-TCH-SP staining in the bone matrix suggests that removal of sulfated glycoconjugates may be a requisite for expansion of initial calcification sites and/or complete calcification.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 2 (1968), S. 1-19 
    ISSN: 1432-0827
    Keywords: Collagen ; Hydroxyapatite ; Keratin ; Enamel ; Calcification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
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  • 8
    ISSN: 1432-0827
    Keywords: Collagen ; 14C-Proline ; Growth ; Bone ; Teeth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Zusammenfassung Das Ausmaß, bis zu welchem Austausch- und Wiederverwendungsprozesse der mineralen Tracer die Messungen des mineralen Skelett-Auf- und Abbaues beeinflussen können, wurde ausgewertet; zu diesem Zweck wurde die Geschwindigkeit des Auftretens und Verschwindens von85Sr und von14C-Prolin-Hydroxyprolin in Knochen und Zähnen von wachsenden Ratten während der 12 auf die simultane parenterale Injektion dieser Tracer folgenden Tage verglichen. Der Ausdruck für die relative Geschwindigkeit des Kollagen-Auf- und Abbaues, bei welchem im Gegensatz zum Mineralmetabolismus kein Mitwirken des Austauschphänomens vermutet wird, basiert auf der Umwandlung von14C-Prolin zu14C-Hydroxyprolin; die spezifische Aktivität des letzteren wurde bestimmt. Aus der spezifischen Aktivität des Minerals sowie jener des Kollagens konnten die Geschwindigkeit und die Art des Wachstums der untersuchten Proben ersehen werden, d.h.schnelles Wachstum und ein kurzes Zeitintervall zwischen Bildung und Resorption des Gewebes imKnochen der Metaphyse, die auch die knorpelige Wachstumsplatte enthält, und andererseitslangsames Wachstum und längeres Zeitintervall (länger als die 12 Tage des Experimentes) zwischen Bildung und Resorption des Gewebes imKnochen der Diaphyse und in den Schneidezähnen. Immerhin fiel die spezifische Aktivität des Kollagen/Mineral-Anteils im Knochen der Metaphyse während dem 4–12tägigen Zeitintervall auf die Hälfte, im Gegensatz zum Knochen der Diaphyse und der Schneidezähne, bei welchen während dieser Zeitspanne kein Unterschied in diesem Verhältnis beobachtet wurde. Diese Ergebnisse zeigen, daß Kollagen in der Wachstumszone der Metaphyse durch Resorption verschwindet, bevor es ganz mineralisiert ist, und daß der Austausch ein relativ unwichtiger Faktor in der Kinetik auf lange Sicht des Knochenminerals ist.
    Notes: Abstract The extent to which exchange and reutilization processes of mineral tracers affect skeletal mineral accretion and resorption measurements was evaluated by comparing the rates of appearance and disappearance of85Sr and14C-proline-hydroxyproline in bones and teeth in growing rats for 12 days following simultaneous parenteral injection of these tracers. Expressions for the relative rates of collagen synthesis and breakdown, which unlike mineral metabolism are considered not to be complicated by exchange phenomena, were based on14C-proline conversion to14C-hydroxyproline; the specific activity of the latter was determined. Both the mineral and the collagen specific activities reflected the rates and patterns of growth of the samples assayed; rapid growth and a short interval of time between formation and resorption of tissue in themetaphyseal bone which contains the cartilagineous growth plate, slow growth and an interval of time between formation and resorption of tissue indiaphyseal bone and incisor teeth which is longer than the 12 days of the experiment. However, in metaphyseal bone the specific activity collagen/mineral ratio dropped by one half during the 4–12 day interval in contrast to diaphyseal bone and incisor teeth in which no change in this ratio was observed during this period of time. The data indicate that collagen in the metaphyseal growth zone is removed by resorption before it has become fully mineralized, and that exchange is a relatively unimportant factor in the long term kinetics of bone mineral.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 2 (1968), S. 20-29 
    ISSN: 1432-0827
    Keywords: Bone Atrophy ; Bone Resorption ; Calcium ; Collagen ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Atrophie osseuse d'immobilisation était induite par section de la plexus brachial et/ou désarticulation de la coude. Après 9 bis 12 semaines de désuétude huméri intactes furent examinés par rayons X et leur qualités physiques déterminés. Les humérientiers furent isolés, dégraissés, desséchés au poids constant, et leur teneur en cendre d'os et collagène déterminés. Huit des 10 huméri immobilisés monstrérent radiodensité diminué. La jambe inusitée monstra perte parallèle en poids sec et poids sans gras (−23.2%), en collagène (−25.3%), et en cendre d'os (−26.1%) en comparaison de la jambe normale. Les données monstrèrent que la portion plus grande du tissu osseux perdu en atrophie osseuse d'immobilisation est remplacée par de l'eau, du gras, et des autres matériels organiques inconnus plutôt que par tissu fibreux, et que collagène est perdu en proportion du minéral. La perte proportionellement plus grande du collagène et de la cendre d'os que du poids sec et poids san gras semble dû à une augmentation du matériel organique, non-collagéne, non-lipide, kprobablement protéine.
    Abstract: Zusammenfassung Immobilisations-Knochenatrophie wurde in 10 erwachsenen Hunden herbeigeführt durch Brachialplexusschnitt und/oder Ellenbogenexartikulation. Nach 9–12 Wochen der Immobilisation wurden die intakten Humeri unter Röntgenstrahlen untersucht und ihre physischen Eigenschaften bestimmt. Derintakte Humerus wurde isoliert, entfettet, zu konstantem Gewicht getrocknet und der Knochenaschengehalt und Kollagengehalt bestimmt. Acht der 10 experimentellen (immobilisierten) Humeri demonstrierte Beweis von verringerter Röntgendichte. Die immobilisierte Extremität zeigte ähnlichen Verlust in trockenem, fettfreiem Gewicht (−23,2%) in Kollagen (−25.3%) und Knochenasche (−26,1%) im Vergleich zur normalen Extremität. Die Date deuten an, daß der Hauptanteil des Verlustes des Knochengewebes (bei Immobilisations-Knochenatrophie) von Wasser, Fett und anderen unidentifizierten organischen Substanzen ersetzt wird, als von Faserngewebe und daß Kollagen und Knochenasche im gleichen Verhältnis verloren gehen. Der größere, proportionale Verlust an Kollagen und Knochenasche, eher als der Verlust an fettfreiem Gewicht, scheint in der Zunahme an nicht kollagener, nicht lipoider, organischer Substanz, vermutlich Protein, zu liegen.
    Notes: Abstract Disuse bone atrophy was induced in 10 adult dogs by means of brachial plexus section and/or elbow disarticulation. After 9 to 12 weeks of disuse intact humeri were examined by X-ray, and their physical properties determined. Thewhole humeri were isolated, defatted, dried to constant weight, and their mineral and collagen content determined. Eight out of 10 experimental (non-used) humeri demonstrated evidence of decreased radiodensity. The non-used limb demonstrated parallel loss in dry, fat-free weight (−23.2%), in collagen (−25.3%), and in mineral (−26.1%), as compared to the normal limb. The data indicated that the major portion of the lost bone tissue in disuse osteoporosis is replaced by water, fat, and other unidentified organic materials rather than fibrous tissue, and that collagen is lost in equal proportion to mineral. The proportionatelly greater loss of collagen and mineral than of dry, fat-free weight appears to be due to an increase of non-collagenous, non-lipid organic material, presumably protein.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 2 (1968), S. 214-228 
    ISSN: 1432-0827
    Keywords: Calcinosis ; Calcification ; Cartilage ; Collagen ; Mineral metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Les facteurs, influençant la vitesse et l'intensité du phénomène d'association des ions calcium et phosphates avec des fibres contenant du collagène, et préparés à partir du tendon de boeuf par deux méthodes d'extraction différentes, ont été étudiés. Les fibres, obtenues par ces deux méthodes, nécessitent spécifiquement du phosphate pour absorber du calcium et vice versa. L'absorption ionique des deux préparations est inhibée par du Mg++, du pyrophosphate et un peptide acidique, isolé du sérum humain. Alors que les fibres contenant du collagène, préparées selon les deux méthodes, présentent une absorption ionique à des vitesses sensiblement identiques, seule une des méthodes donne une matrice réagissant positivement à la technique de coloration au nitrate d'argent de von Kossa. Etant donné que les deux critères de calcification sont intéressés de façon identique par des conditions de réaction et par des inhibiteurs, il apparait que les deux facteurs sont des manifestations de différents stades de calcification et que des études d'absorption ionique fournissent une base quantitative d'appréciation de la calcification, pouvant être d'importance pour l'étude du mécanisme et de contrôle de la minéralisation tissulaire.
    Abstract: Zusammenfassung Überprüft wurden die Faktoren, welche Geschwindigkeit und Ausmaß der Erscheinung beeinflussen, wobei Calcium- und Phosphationen sich mit den kollagenhaltigen, durch zwei verschiedene Extraktionsmethoden aus Rindersehnen gewonnenen Fasern eng zusammenbinden. Die mit beiden Methoden zubereiteten Fasern benötigen spezifisch Phosphat für die Calciumaufnahme und Calcium für die Phosphataufnahme. Die Ionenaufnahme beider Arten wird durch Mg++, Pyrophosphat und saure, aus dem menschlichen Serum isolierte Peptide gehemmt. Während die nach beiden Methoden präparierten kollagenhaltigen Fasern eine Ionenaufnahme von beinahe gleicher Geschwindigkeit verursachen, ergibt nur eine dieser Methoden eine Matrix, die mit der Silbernitratfärbung nach vonKossa positiv reagiert. Da beide Calcifikationskriterien gleicherweise durch Reaktionsbedingungen und Inhibitoren beeinflußt werden, wird daraus geschlossen, daß beide Erscheinungen verschiedener Stadien des Gesamtcalcifikationsprozesses sind. Untersuchungen über die Ionenaufnahme ergeben eine quantitative Angabe der Verkalkung, welche für die Erforschung des Mechanismus und der Kontrolle der Mineralisation der Gewebe wichtig sein könnte.
    Notes: Abstract Factors that influence the rate and extent of the phenomenon in which calcium and phosphate ions become firmly associated with collagen-containing fibers prepared from beef tendon by two different extraction methods have been investigated. The fibers produced by both methods specifically require phosphate for calcium uptake and calcium is required for phosphate uptake. Ion uptake by both types is inhibited by Mg++, pyrophosphate, and an acidic peptide isolated from human serum. Whereas the collagen-containing fibers prepared by both methods induce ion uptake at nearly identical rates, only one of the methods produced a matrix that gives a positive response to the silver nitrate staining technique of von Kossa. Since both criteria of calcification are similarly influenced by reaction conditions and inhibitors, it is concluded that both are manifestations of different stages of the overall calcification process and that studies of ion uptake provide a quantitative assessment of calcification which could be of importance for investigating the mechanism and control of tissue mineralization.
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