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  • Electronic Resource  (15)
  • Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry  (6)
  • Evolution  (5)
  • Molecular Cell Biology  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Incremental growth of a large volume, chemically zoned magma body: a study of the tephra sequence beneath the Rainier Mesa ash flow sheet of the Timber Mountain Tuff (1994)
    Springer
    Bulletin of volcanology 56 (1994), S. 377-385 
    Details
    ISSN: 1432-0819
    Keywords: Key wordsZoned magma body ; Chemical variation ; ash-flow sheets ; Tephra sequence ; Differentiation ; time constraints ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract The Rainier Mesa ash-flow is a large (1200 km3), 11.6 My old, chemically zoned unit that ranges in composition from 55 to 76% SiO2– one of the largest chemical ranges ever observed in a large volume ash-flow sheet. Two chemical trends occur in this sheet, a low silica (55–66% SiO2) and a high silica (〉66% SiO2) trend. Ninety per cent of the Rainier Mesa sheet occurs in the high silica trend. Immediately beneath the Rainier Mesa sheet is a thick tephra sequence. The chemical variation of this sequence is nearly equivalent to the high silica portion of the Rainier Mesa ash-flow sheet (about 66–78% SiO2). Throughout the tephra sequence numerous small ash-flow layers occur, and each ash-flow layer is chemically zoned from more evolved at the base to less evolved at the top. This is consistent with having been erupted from a zoned magma body. The lowest silica tephra units are at the base of the sequence and the highest silica units are at the top – that is, the large-scale chemical trend of the entire sequence is opposite to that of the individual ash-flow layers. These ash-flow layers are of very small volume. The tephra sequence provides a unique record of the incremental development of the zoned, high silica portion of the Rainier Mesa magma body.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00326463
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  • 2
    Electronic Resource
    Electronic Resource
    Analyses of ribosomal RNA sequences from glaucocystophyte cyanelles provide new insights into the evolutionary relationships of plastids (1995)
    Springer
    Journal of molecular evolution 41 (1995), S. 203-210 
    Details
    ISSN: 1432-1432
    Keywords: Cyanelles ; Cyanophora paradoxa ; Endosymbiosis ; Evolution ; Glaucocystophyta ; Glaucophyta ; Phylogeny ; Plastid ; 16S ribosomal RNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Glaucocystophyte algae (sensu Kies, Berl. Deutsch. Bot. Ges. 92, 1979) contain plastids (cyanelles) that retain the peptidoglycan wall of the putative cyanobacterial endosymbiont; this and other ultrastructural characters (e.g., unstacked thylakoids, phycobilisomes) have suggested that cyanelles are “primitive” plastids that may represent undeveloped associations between heterotrophic “host” cells (i.e., glaucocystophytes) and cyanobacteria. To test the monophyly of glaucocystophyte cyanelles and to determine their evolutionary relationship to other plastids, complete 16S ribosomal RNA sequences were determined for Cyanophora paradoxa, Glaucocystis nostochinearum, Glaucosphaera vacuolata, and Gloeochaete wittrockiana. Plastid rRNAs were analyzed with the maximum-likelihood, maximumparsimony, and neighbor joining methods. The phylogenetic analyses show that the cyanelles of C. paradoxa, G. nostochinearum, and G. wittrockiana form a distinct evolutionary lineage; these cyanelles presumably share a monophyletic origin. The rDNA sequence of G. vacuolata was positioned within the nongreen plastid lineage. This result is consistent with analyses of nuclear-encoded rRNAs that identify G. vacuolata as a rhodophyte and support its removal from the Glaucocystophyta. Results of a global search with the maximumlikelihood method suggest that cyanelles are the first divergence among all plastids; this result is consistent with a single loss of the peptidoglycan wall in plastids after the divergence of the cyanelles. User-defined tree analyses with the maximum-likelihood method indicate, however, that the position of the cyanelles is not stable within the rRNA phylogenies. Both maximumparsimony and neighbor-joining analyses showed a close evolutionary relationship between cyanelles and nongreen plastids; these phylogenetic methods were sensitive to inclusion/exclusion of the G. wittrockiana cyanelle sequence. Base compositional bias within the G. wittrockiana 16S rRNA may explain this result. Taken together the phylogenetic analyses are interpreted as supporting a near-simultaneous radiation of cyanelles and green and nongreen plastids; these organelles are all rooted within the cyanobacteria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00170674
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  • 3
    Electronic Resource
    Electronic Resource
    Incremental growth of a large volume, chemically zoned magma body: a study of the tephra sequence beneath the Rainier Mesa ash flow sheet of the Timber Mountain Tuff (1994)
    Springer
    Bulletin of volcanology 56 (1994), S. 377-385 
    Details
    ISSN: 1432-0819
    Keywords: Zoned magma body ; Chemical variation ash-flow sheets ; Tephra sequence ; Differentiation time constraints ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract The Rainier Mesa ash-flow is a large (1200 km3), 11.6 My old, chemically zoned unit that ranges in composition from 55 to 76% SiO2 — one of the largest chemical ranges ever observed in a large volume ash-flow sheet. Two chemical trends occur in this sheet, a low silica (55–66% SiO2) and a high silica (〉66% SiO2) trend. Ninety per cent of the Rainier Mesa sheet occurs in the high silica trend. Immediately beneath the Rainier Mesa sheet is a thick tephra sequence. The chemical variation of this sequence is nearly equivalent to the high silica portion of the Rainier Mesa ash-flow sheet (about 66–78% SiO2). Throughout the tephra sequence numerous small ash-flow layers occur, and each ash-flow layer is chemically zoned from more evolved at the base to less evolved at the top. This is consistent with having been erupted from a zoned magma body. The lowest silica tephra units are at the base of the sequence and the highest silica units are at the top — that is, the large-scale chemical trend of the entire sequence is opposite to that of the individual ash-flow layers. These ash-flow layers are of very small volume. The tephra sequence provides a unique record of the incremental development of the zoned, high silica portion of the Rainier Mesa magma body.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00326463
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  • 4
    Electronic Resource
    Electronic Resource
    Thermotoga maritima sp. nov. represents a new genus of unique extremely thermophilic eubacteria growing up to 90°C (1986)
    Springer
    Archives of microbiology 144 (1986), S. 324-333 
    Details
    ISSN: 1432-072X
    Keywords: Evolution ; Eubacteria ; Thermophile ; Anaerobe ; Thermotoga maritima
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A novel type of bacterium has been isolated from various geothermally heated locales on the sea floor. The organisms are strictly anaerobic, rod-shaped, fermentative, extremely thermophilic and grow between 55 and 90°C with an optimum of around 80°C. Cells show a unique sheath-like structure and monotrichous flagellation. By 16S rRNA sequencing they clearly belong to the eubacteria, although no close relationship to any known group could be detected. The majority of their lipids appear to be unique in structure among the eubacteria. Isolate MSB8 is described as Thermotoga maritima, representing the new genus Thermotoga.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00409880
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  • 5
    Electronic Resource
    Electronic Resource
    Fervidobacterium islandicum sp. nov., a new extremely thermophilic eubacterium belonging to the “Thermotogales” (1990)
    Springer
    Archives of microbiology 154 (1990), S. 105-111 
    Details
    ISSN: 1432-072X
    Keywords: Eubacterium ; Thermophile ; Evolution ; Fervidobacterium ; Lipids ; Thermotoga
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An extremely thermophilic anaerobic fermentative eubacterium growing at temperatures between 50 and 80°C (opt.: 65°C) was isolated from an Icelandic hot spring. The cells were Gram-negative motile rods, about 1.8 μm in length, and 0.6 μm in width occurring singly and in pairs. About 50% of the cells formed large spheroids at one end similar to Fervidobacterium nodosum. The new isolate H 21 differed from Fervidobacterium nodosum by a 6 mol % higher GC-content of its DNA (41 mol %), its ability to grow on cellulose, and insignificant DNA homology. The lipids of isolate H 21 were similar to that of members of “Thermotogales”. 16S rRNA sequencing of isolate H 21 and Fervidobacterium nodosum indicated (a) that isolate H 21 represents a new species of the genus Fervidobacterium which we name Fervidobacterium islandicum and (b) that the genus Fervidobacterium belongs to the “Thermotogales” branch.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00423318
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  • 6
    Electronic Resource
    Electronic Resource
    Control of mouse myoblast commitment to terminal differentiation by mitogens (1980)
    New York, N.Y. : Wiley-Blackwell
    Journal of Supramolecular Structure 14 (1980), S. 483-498 
    Details
    ISSN: 0091-7419
    Keywords: myoblast differentiation ; muscle cell culture ; mitogens ; growth factors ; myoblast cell lines ; Life Sciences ; Molecular Cell Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Regulation of the transition of mouse myoblasts from proliferation to terminal differentiation was studied with clonal density cultures of a permanent clonal myoblast cell line. In medium lacking mitogenic activity, mouse myoblasts withdraw from the cell cycle, elaborate muscle-specific gene products, and fuse to form multinucleated myotubes. Addition of a purified mitogen, fibroblast growth factor, to mitogen-depleted medium stimulates continued proliferation and prevents terminal differentiation. When mitogens are removed for increasing durations and then refed, mouse myoblasts irreversibly commit to terminal differentiation: after 2-4 h in the absence of mitogens, myoblasts withdraw from the cell cycle, elaborate muscle-specific gene products, and fuse in the presence of mitogens that have been fed back. Population kinetics of commitment determined with 3H-thymidine labeling and autoradiography suggest the following cell-cycle model for mouse myoblast commitment: (1) if mitogens are present in the extracellular environment of myoblasts in G1 of the cell cycle, the cells enter S and continue through another cell cycle; (2) if mitogens have been absent for 2 or more hours, cells in G1 do not enter S; the cells commit to differentiate, permanently withdraw from the cell cycle (will not enter S if mitogens are refed), and they subsequently elaborate acetylcholine receptors and fuse (even if mitogens are refed); (3) cells in other phases of the cell cycle continue to transit the cell cycle in the absence of mitogens until reaching the next G1. The commitment kinetics and experiments with mitotically synchronized cells suggest that the commitment “decision” is made during G1. Present results do not, however, exclude commitment of some cells in other phases of the cell cycle.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jss.400140407
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  • 7
    Electronic Resource
    Electronic Resource
    Human placental cell surface antigens: Expression by cultured cells of diverse phenotypic origin (1979)
    New York, N.Y. : Wiley-Blackwell
    Journal of Supramolecular Structure 11 (1979), S. 503-515 
    Details
    ISSN: 0091-7419
    Keywords: glycoproteins ; two-dimensional electrophoresis ; differentiation ; Life Sciences ; Molecular Cell Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The present work examined the expression of cell surface glycoprotein antigens in cultured human cell lines. The set of glycoproteins studied was defined by their immunoreactivity with antiserum developed to Triton-solubilized extracts of placental brush border membranes. Studies were performed using cell lines of trophoblastic (BeWo, JEG-3) and nontrophoblastic (Chang liver cells) origin, as well as diploid fibroblast cell lines (WI-38, GM-38).Antiplacental brush border antiserum reacts with at least 19 distinct antigens present in placental membrane preparations, each of which can be resolved and identified in two-dimensional electrophoresis. The subunit molecular weight and isoelectric point for all components were defined by their positions in the two-dimensional matrix. Thirteen of these could be detected among the five cell lines examined by lactoperoxidase-catalyzed cell surface iodination. One of these 13 antigens has been identified as the placental isoenzyme of alkaline phosphatase (PAP). The expression of this component is limited to choriocarcinonia cells and Chang liver cells and it is not present in diploid fibroblasts. Under normal circumstances expression of PAP is unique to the differentiated placenta but has been frequently demonstrated in both trophoblastic and nontrophoblastic neoplasms.Two other antigens are variably expressed among the different cell types examined in the present study and their presence or absence was independent of the trophoblastic, epithelial nontrophoblastic, or fibroblastic origin of the cells.Ten surface antigens were expressed in all five cell lines. Six of these had previously been found common to membranes from three adult differentiated tissues, including liver and kidney, as well as placenta (Wada et al, J Supramol Struc 10(3):287-305, 1979). The presence of this set of antigens in cultured cells as well extends the possibility that these are ubiquitously expressed on human cell surfaces. Two other antigens observed in all cultured cells had been found in both placental and either kidney or liver membranes and may represent common functions shared by many tissues which are also necessary for growth in vitro. The two remaining placental antigens seen in all cultured cells have previously been shown to be absent in adult tissues. Their presence in cultured cells but not in the membranes of resting differentiated tissues may signify the expression of glycoproteins characteristic of trophoblasts in all cells adapted to growth in culture.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jss.400110409
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  • 8
    Electronic Resource
    Electronic Resource
    Regulation of glucose carriers in chick fibroblasts (1977)
    New York, N.Y. : Wiley-Blackwell
    Journal of Supramolecular Structure 7 (1977), S. 499-513 
    Details
    ISSN: 0091-7419
    Keywords: glucose ; carrier ; regulation ; transport ; Life Sciences ; Molecular Cell Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The derepression of glucose transport initiated by removing glucose from the incubation medium requires both protein and RNA synthesis. The synthesis and accumulation of putative mRNA for the carrier protein(s) can be demonstrated by inhibiting protein synthesis with cycloheximide (2 μg/ml). Release from inhibition with simulataneous addition of actionmycin D (1-5 μg/ml) results in a burst of carrier synthesis that achieves virtually maximal derepression in 4-6 h. An external energy source provided by a “nonrepressive” sugar (D-fructose, D-xylose) or by pyruvate is required to accomplish carrier synthesis. Previous failure to demonstrate mRNA accumulation was due to the depletion of energy in the starved cells. Glucose acts as a repressor at a posttranscriptional step, probably at the level of turnover of formed carrier.The protection of formed carrier in the absence of glucose and by inhibitors of protein synthesis even in the presence of glucose has encouraged conjecture that a protease is activated by a metabolic product of glucose that is analogous to a co-repressor. The glucose metabolite either activates the protease by direct interaction with it or alters the conformation of the carrier to expose a critical region to protease attack. Indeed the regulation of carrier density in the membrane of chick fibroblasts may be achieved entirely by carrier inactivation, the rate of which is a function of glucose concentration in the culture medium.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jss.400070319
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  • 9
    Electronic Resource
    Electronic Resource
    Activation of cyclic AMP-dependent protein kinase and stimulation of protein phosphorylation in response to adenosine in C-1300 murine neuroblastoma (1979)
    New York, N.Y. : Wiley-Blackwell
    Journal of Supramolecular Structure 10 (1979), S. 125-135 
    Details
    ISSN: 0091-7419
    Keywords: protein phosphorylation ; cAMP-dependent protein kinases ; adenosine on cyclic AMP ; C1300 neuroblastoma ; Life Sciences ; Molecular Cell Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: DEAE-cellulose chromatography of the 20,000g supernatant fraction of homogenates of C-1300 murine neuroblastoma (clone N2a) yields one major and two minor peaks of cyclic AMP-dependent protein kinase activity. Assessment of the endogenous activation state of the enzyme(s) reveals that the enzyme is fully activated by the treatment of whole cells with adenosine (10 μM) in the presence of the phosphodiesterase inhibitor Ro 20 1724 (0.7 mM). This treatment produces a large elevation in the cyclic AMP content of the cells. The treatment of whole cells with adenosine alone (1-100 μM) or Ro 20 1724 alone (0.1-0.7 mM) produces minimal elevations in cyclic AMP but nevertheless causes significant activations of cyclic AMP-dependent protein kinase. The autophosphorylation of whole homogenates of treated and untreated cells was studied using [γ-32P] ATP, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Treatments which activate cyclic AMP-dependent protein kinase selectively stimulate the incorporation of 32P into several proteins. This stimulation is most prominent in the 15,000-dalton protein band. The addition of cyclic AMP to phosphorylation reactions containing homogenate of untreated cells stimulates the phosphorylation of the same protein bands. These results indicate that adenosine may have regulatory functions through its effect on the cyclic AMP: cyclic AMP-dependent protein kinase system.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jss.400100203
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  • 10
    Electronic Resource
    Electronic Resource
    Sex pheromone blend of Manduca sexta: Responses of central olfactory interneurons to antennal stimulation in male moths (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 10 (1989), S. 281-291 
    Details
    ISSN: 0739-4462
    Keywords: antennal lobe ; electrophysiology ; olfaction ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Recently, chemical analysis of solvent rinses of the external surfaces of pheromone glands from female Manduca sexta revealed a blend of 12 aldehydes, including the previously identified sex pheromone component, (E,Z)-10,12-hexadecadienal (bombykal). Previous electrophysiological studies showed that olfactory (deutocerebral) interneurons in the antennal lobes of males exhibited a wide range of responsiveness to pheromonal stimulation of the ipsilateral antenna. These experiments were performed with crude extracts of pheromone glands as well as two synthetic compounds: the major pheromone component, bombykal, and (E,Z)-11,13-pentadecadienal, a mimic of a second component of the female's pheromone blend. Using intracellular methods, we have now reexamined similar olfactory interneurons, using each of the 12 chemically identified components as well as synthetic blends of various combinations of them. Eight of the 12 components isolated from female glands elicited some form of response in olfactory interneurons in males. In accordance with biochemical and behavioral data, the most potent are bombykal and two trienals, (E,E,E)- and (E,E,Z)-10,12,14-hexadecatrienal. We also conclude that the C15 dienal is selective for one of the trienal receptors on the antenna, but is much less potent than the natural trienal stimulant.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940100404
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