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  • LUNAR AND PLANETARY EXPLORATION  (9)
  • Key words: Osteoclast — Differentiation — Bone resorption — Prostaglandins.  (1)
  • Key words: Osteoclast — Monocyte — Macrophage — Differentiation — Bone Resorption.  (1)
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  • 1
    ISSN: 1432-0827
    Schlagwort(e): Key words: Osteoclast — Differentiation — Bone resorption — Prostaglandins.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract. The effect of prostaglandins (PGs) on osteoclast differentiation, an important point of control for bone resorption, is poorly understood. After an initial differentiation phase that lasts at least 4 days, murine monocytes, cocultured with UMR106 osteoblastic cells (in the presence of 1,25-dihydroxyvitamin D3) give rise to tartrate-resistant acid phosphatase (TRAP) positive osteoclast-like cells that are capable of lacunar bone resorption. PGE2 strongly inhibits TRAP expression and bone resorption in these cocultures. To examine further the cellular mechanisms associated with this inhibitory effect, we added PGE2 to monocyte/UMR106 cocultures at specific times before, during, and after this initial 4-day differentiation period. To determine whether this PGE2 inhibition was dependent on the type of stromal cell supporting osteoclast differentiation, we also added PGE2 to cocultures of monocytes with ST2 preadipocytic cells. Inhibition of bone resorption was greatly reduced when the addition of PGE2 to monocyte/UMR106 cocultures was delayed until the fourth day of incubation; when delayed until the seventh day, inhibition did not occur. PGE2 inhibition of bone resorption was concentration-dependent and at 10−6 M was also mediated by PGE1 and PGF2α. In contrast to its effects on monocyte/UMR106 cocultures, PGE2 stimulated bone resorption in monocyte/ST2 cocultures. Both ST2 cells and UMR106 cells were shown to express functional receptors for PGE2. These results show that PGs strongly influence the differentiation of osteoclast precursors and that this effect is dependent not only on the type and dose of PG administered, but also on the nature of the bone-derived stromal cell supporting this process.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 62 (1998), S. 527-531 
    ISSN: 1432-0827
    Schlagwort(e): Key words: Osteoclast — Monocyte — Macrophage — Differentiation — Bone Resorption.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract. Mononuclear precursors of the human osteoclast have been identified in both bone marrow and the circulation in man, but osteoclast membership of the mononuclear phagocyte system (MPS) and its precise cellular ontogeny remain controversial. We isolated human hematopoietic marrow cells, blood monocytes, and peritoneal macrophages and incubated each of these cell populations with UMR106 osteoblast-like cells on glass coverslips and dentine slices in both the presence and absence of 1,25 dihydroxyvitamin D3 (1,25(OH)2D3), macrophage-colony stimulating factor (M-CSF), and dexamethasone. Cells isolated from peripheral blood and peritoneal dialysis fluid were positive only for monocyte/macrophage markers (CD11a, CD11b, CD14, and HLA-DR) and negative for osteoclast markers [tartrate-resistant acid phosphatase (TRAP), vitronectin reception (VNR), and calcitonin (CT) receptors and did not form resorption pits on dentine slices after 24 hours in culture. Similarly marrow cells did not form resorption pits on dentine slices after 24 hours in culture. However, after 14 days in co-culture with UMR106 cells, in the presence of 1,25(OH)2D3 and M-CSF, numerous TRAP, CT receptor, and VNR-positive multinucleated cells capable of extensive lacunar resorption were formed in co-cultures of all these preparations. The presence of 1,25 (OH)2D3, M-CSF, and UMR106 were absolute requirements for osteoclast differentiation. It is concluded that precursor cells capable of osteoclast differentiation are present in the marrow compartment, the monocyte fraction of peripheral blood, and in the macrophage compartment of extraskeletal tissues and that these cells are capable of differentiating into mature functional osteoclasts. These findings argue in favor of osteoclast membership of the human MPS.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2019-07-13
    Beschreibung: Breccia 73255 contains sparse small clasts of basalts that have mare affinities; the basalts are members of a single differentiated suite. The clasts have been fractured throughout and locally granulated. Textural and compositional evidence indicates that the fracturing and granulation were produced by the 73255 breccia-forming event, and this event took place before the basalts had completely solidified. Thus, it appears that the eruption of the basalts took place at about the same time as the formation of the 73255 breccia, about 3.9 b.y. ago. The mineral assemblages and modes of the basalt clasts are those typical of mare basalts, but the clasts are not identical in detail with any basalts returned from the mare surfaces. They are instead most similar to the 14053-type basalts from the Apollo 14 site.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Lunar and Planetary Science Conference; Mar 17, 1980 - Mar 21, 1980; Houston, TX
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Publikationsdatum: 2019-07-13
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Lunar and Planetary Science Conference; Mar 19, 1979 - Mar 23, 1979; Houston, TX
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Publikationsdatum: 2019-07-13
    Beschreibung: Laser (Ar-39)-(Ar-40) studies of clasts and groundmass in breccia 73255 are presented. They show a variety of ages indicating that some materials lost argon from sites that outgas at low temperature, while other materials have retained argon generated before the breccia-forming event. The estimate for the time of the breccia-forming event from thermal release studies is compared to the upper limit of the event from the laser studies; this work also shows that ages in excess of 4.0 G.y. determined on rocks containing devitrified maskelynite clasts probably have no chronological significance.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Lunar and Planetary Science Conference; Mar 19, 1979 - Mar 23, 1979; Houston, TX
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Publikationsdatum: 2019-07-13
    Beschreibung: A study of two clasts of coarse-grained anorthositic-noritic-troctolitic-suite norites from the fragment-laden melt rock 73255 is presented. Both clasts are igneous rocks crystallized from melts that were probably internally generated; clast 27,80 is a cumulate, and the parent magmas of both rocks probably crystallized below the lunar surface. Despite similar history, the parent rocks of the two clasts appear to be derived from distinct magma types: the 27,80 is characterized by plagioclase and orthopyroxene as the major constituents and by a high K, Nb, and Zr content, while the 27,45 type also contains augite and has a low content of K, Nb, and Zr.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Lunar and Planetary Science Conference; Mar 19, 1979 - Mar 23, 1979; Houston, TX
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Publikationsdatum: 2019-07-13
    Beschreibung: Eleven splits from the mafic-mineral-rich part of anorthosite 60025 were studied in order to establish the exact nature and causes of compositional variations in the minerals of lunar ferroan anorthosites. All splits were analyzed by INAA, and five were studied intensively by petrologic techniques. All splits were found to have similar cataclastic textures and show textural evidence of at least two episodes of deformation. The whole-rock split contains mafic minerals having a wide range of compositions and is probably polymict. It is suggested that the rare-earth patterns for all splits can be duplicated safactorily, assuming that the equilibrium liquids had flat, or nearly flat, chondrite-normalized rare-earth patterns. The plagioclases in all splits were found to be identical. Data obtained indicate that in ferroan anorthosites An content in plagioclase and mg' of associated mafic minerals are not strongly correlated.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Lunar and Planetary Science Conference; Mar 12, 1990 - Mar 16, 1990; Houston, TX; United States
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2019-07-13
    Beschreibung: Results of a study of 16 samples from the anorthositic ferroan subgroup, or 'typical' ferroan anorthosites, are reported. The presence of heterogeneous, bimodal, and/or trimodal pyroxene compositions suggests that some of the anorthosites are polymict rocks; however, they are composed entirely of ferroan-anorthosite-suite lithologies. It is suggested that complex processes operated during the formation of the ferroan anorthosites. It is argued that original igneous compositional characteristics were altered during and/or after crystallization. Processes operative during anorthosite formation may have included some mixing of different melts, trapping of variable amounts of intercumulus liquid, postcrystallization redistribution of elements, or perturbations both during adcumulus growth and subsequent to crystallization by impact events.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 98; E5; p. 9089-9105.
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Publikationsdatum: 2019-07-13
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Lunar and Planetary Science Conference; Mar 17, 1980 - Mar 21, 1980; Houston, TX
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Publikationsdatum: 2019-07-13
    Beschreibung: A petrologic study of crystalline lithic clasts from feldspathic breccia 67975, collected on the rim of North Ray crater at the Apollo 16 site, is presented. A light gray group has been identified as granulitic breccias, and a dark gray group has been identified as feldspathic microporphyritic melt breccias. It is suggested that complete homogenization of the minerology of the granulitic breccias may have been prevented by their incorporation into the 67975 fragmental breccia, and that metamorphism of the clasts may have been interrupted by this breccia forming event.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Lunar and Planetary Science Conference; Mar 14, 1988 - Mar 18, 1988; Houston, TX; United States
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
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