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  • Organic Chemistry  (1,383)
  • Life and Medical Sciences  (1,061)
  • 1980-1984  (2,444)
  • 1940-1944
  • 1981  (1,289)
  • 1980  (1,155)
Collection
Keywords
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  • 1980-1984  (2,444)
  • 1940-1944
Year
  • 1
    Electronic Resource
    Electronic Resource
    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010101
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  • 2
    Electronic Resource
    Electronic Resource
    Tubulin nucleation and assembly in mitotic cells: Evidence for nucleic acids in kinetochores and centrosomes (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 1-15 
    Details
    ISSN: 0886-1544
    Keywords: centrosomes ; kinetochores ; microtubule initiation ; nuclease enzymes ; electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A lysed cell system was used to study the organelle structure and nucleation of exogenous tubulin at kinetochores and centrosomes in mitotic PtK2 cells. We have used this lysed cell system in conjunction with nuclease digestion experiments to determine which specific nucleic acids (DNA or RNA) are involved in either the structure and/or microtubule-initiating capacity of kinetochores and centrosomes. The results indicate that DNase I specifically decondenses the kinetochore plate structure, with the eventual loss in the ability of the chromosomes to nucleate microtubule assembly. DNase I had no effect on either the structure or nucleating capacity of centrosomes. Both RNase T1 and RNase A specifically attacked the amorphous pericentriolar material of the centrosomes, with a concomitant loss in the ability of this material to nucleate microtubule formation. Neither RNase appeared to affect the structure or nucleating capacity of the kinetochore. Therefore, the two types of nucleases appear to exert preferential effects on the different types of microtubule initiation sites in mitotic mammalian cells. The results suggest that DNA is a major component of the kinetochore, while RNA is a major component of the amorphous pericentriolar material. These findings support the concept that microtubule initiation sites in mitotic cells contain nucleic acids which are essential for the structural and functional integrity of the sites.
    Additional Material: 45 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010102
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  • 3
    Electronic Resource
    Electronic Resource
    Redistribution of actin and fascin in sea urchin eggs after fertilization (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 31-40 
    Details
    ISSN: 0886-1544
    Keywords: actin ; fascin ; actin cross-linking proteins ; fertilization ; microvilli ; sea urchin eggs ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Following fertilization, the sea urchin egg cortex undergoes a structural change involving the assembly and organization of actin filaments into microvilli. Antifascin localizes this actin cross-linking protein in the microvilli of the fertilized egg cortex but no organized staining is present in the unfertilized cortex. Determination of the actin content of eggs using the DNAase I inhibition assay indicates that actin is about 1.4% of the total protein. Approximately 90% of this actin is soluble in low calcium isotonic extracts of unfertilized eggs while only 60-65% can be recovered in identical extracts of fertilized eggs. Similar measurements for fascin using a radioimmunoassay indicate this molecule represents about 0.3% of the total egg protein, essentially all of which is recovered in low calcium isotonic extracts of unfertilized eggs. After fertilization only 65-70% of this actin cross-linking protein is in the soluble phase. These results demonstrate a markedly different solubility for actin and fascin after fertilization, when the indirect immunofluorescence staining localizes fascin in the microvilli, and are consistent with the idea that fascin organizes newly polymerized actin filaments into the microvillar cores. A consideration of the amounts of actin and fascin incorporated into the cortex after fertilization and the number of microvilli on the egg surface indicates that the measured values are sufficient to account for the observed microvillar elongation.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010104
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  • 4
    Electronic Resource
    Electronic Resource
    Control by calcium of the contractility of Labyrinthula slimeways and of the translocation of Labyrinthula cells (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 17-29 
    Details
    ISSN: 0886-1544
    Keywords: Ca-ion ; Labyrinthula ; contraction ; glycerination ; Ca-reservoir ; cell movement ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Colonies of Labyrinthula, a colonial marine protist, expand by protrusive movements of the specialized slimeways. The movements recorded in time-lapse films are of two types - filopodial and lamellipodial - and occur at rates equivalent to those of cell translocation.Evidence is presented that Ca2+ regulates the contraction of the actomyosin system of filaments present in the slimeways of Labyrinthula. In glycerinated models or in colonies exposed to ionophore A23187 contraction is evidenced by the occurrence of periodic contractions of the slimeways, giving them the appearance of strings of beads. Glycerinated slimeways contract on the addition of Ca2+ and ATP while slimeways provided with ionophore A23187 contract on addition of Ca2+ alone. The concentration required is 1.1 × 10-7 M Ca2+ while concentrations of 6.2 × 10-8 or lower were ineffective. Rates of contraction were measured in time-lapse films which provide evidence that contractions and beading occur everywhere in the slimeway system. When beading occurs, the 6-nm filaments transform from an array of parallel single filaments into an interwoven meshwork.We have identified by pyroantimonate-OsO4 fixation, as possible Ca2+ reservoirs, deposits of Ca2+ in bothrosomes - structures through which cell secretions pass into the slimeways. The electron-dense deposits are located at the base of the bothrosome and disappear after incubation with EGTA. We propose that the translocation of cells as well as the movements of slimeways may be regulated by the cells through the local measured liberation of Ca2+ from the bothrosome where it is sequestered.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970010103
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  • 5
    Electronic Resource
    Electronic Resource
    An analysis of spindle ultrastructure during anaphase of micronuclear division in Tetrahymena (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 41-61 
    Details
    ISSN: 0886-1544
    Keywords: mitosis ; mitotic spindle ; kinetochore ; microtubule ; micronucleus ; Tetrahymena ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mitotic micronuclei were isolated from Tetrahymena thermophila and data on spindle ultrastructure were obtained from serial, transverse sections. Comparison of data from nuclei at meta- and early anaphase with data from nuclei at late anaphase showed that during anaphase, sister kinetochores move from the equator to the spindle poles, but kinetochore translocation occurs without any apparent change in either the number or length of kinetochore microtubules. This unprecedented result is ascribed significance with regard to the mechanism of kinetochore transport since there are only a limited number of ways that result could be achieved. The organization of the peripheral sheath changes during anaphase as evidenced by gaps in the sheath at late anaphase. Numerous kinetochore and non-kinetochore microtubules are located in polar regions of the spindle at late anaphase, whereas those regions contained only peripherally arranged microtubules at earlier stages. Tracking of individual kinetochore microtubules in late anaphase nuclei showed that some of them appeared to become incorporated into the peripheral sheath near the pole. At early and late anaphase, crossbridges connect adjacent microtubules throughout the spindle poleward to the kinetochores, as well as in the interzone.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010105
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  • 6
    Electronic Resource
    Electronic Resource
    Physarum myosin light chain binds calcium (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 63-71 
    Details
    ISSN: 0886-1544
    Keywords: Physarum polycephalum ; myosin light chains ; polyacrylamide gel electrophoresis ; calcium ; cytoplasmic streaming ; actomyosin ATPase regulation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Myosin from the slime mold Physarum polycephalum contains three sizes of polypeptides: a heavy chain and two light chains, LC-1 and LC-2. Using a simple qualitative test for calcium binding by comparing electrophoretic migration of the polypeptides in sodium dodecy1 sulfate (SDS) acrylamide gels in the presence and absence of calcium, we have found that Physarum myosin light chain LC-2 migrates with an apparent molecular weight of 16,900 daltons in the presence of the metal ion chelator ethylene glycol bis (B-aminoethyl ether) N,N′-tetraacetic acid (EGTA). However, if calcium chloride is added to the sample prior to electrophoresis, the apparent molecular weight decreases to 16,100. Lanthanide and cadmium ions, but not magnesium, can substitute for calcium. Because the ionic radii of Ca2+, La3+, and Cd2+ are almost identical, we conclude that Physarum myosin LC-2 possesses a very size-specific binding site for calcium. Physarum myosin LC-1 and the heavy chain give no evidence for binding calcium by this test. Since cytoplasmic streaming in the plasmodium of Physarum requires calcium, our evidence indicates that the calcium-binding property of Physarum myosin LC-2 may be important in regulating the production of force by actomyosin in the ectoplasm. Unexpectedly, the myosin light chain in Physarum capable of binding calcium, LC-2, is the essential light chain, while LC-1 is a member of the regulatory class of myosin light chains [V. T. Nachmias, personal communication]. Until now, essential myosin light chains have not been shown to have high affinity divalent cation binding sites. This means a new version of the myosin-based model for actomyosin regulation by calcium may be required to explain cytoplasmic movement in Physarum, and perhaps in other motile systems involving cytoplasmic myosins as well.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010106
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  • 7
    Electronic Resource
    Electronic Resource
    Video-enhanced contrast, differential interference contrast (AVEC-DIC) microscopy: A new method capable of analyzing microtubule-related motility in the reticulopodial network of allogromia laticollarisDr. D. Lansing Taylor served as executive editor for this communication. (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 291-302 
    Details
    ISSN: 0886-1544
    Keywords: videomicroscopy ; differential interference microscopy ; streaming ; reticulopodial motility ; Allogromia ; microtubules ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A new method called Allen Video-enhanced Contrast, Differential Interference Contrast (AVEC-DIC) microscopy is shown to be sufficiently sensitive to detect several new features of microtubule-related motility in the reticulopodial network of the foraminifer, Allogromia. The method takes advantage of the variable gain and offset features of a binary video camera to operate the DIC microscope under conditions highly favorable for video imaging, but in which the optical image is virtually invisible to the eye yet retains its full information when viewed by a suitable video camera. The improvements are made possible by setting a dé Senarmont compensator to λ/9-λ/4 at maximal working aperture of internally corrected planapochromatic objectives. Under these conditions, the offset feature of the video camera can reject so much stray light from the instrument and specimen that contrast compares favorably with that observed in high-extinction images, and polarizing rectifiers offer scarcely any advantage. Freed from the constraints of the light-limited conditions of DIC microscopy, video images can be recorded 60 times per second, or over 1,000 times the rate of photomicrographs at comparable magnifications under high-extinction conditions.Application of this method to the reticulopodial network of Allogromia has shown that cytoplasmic organelles are translocated only in contact with single microtubules or bundles of microtubules, and that these organelles fail to move when separated from microtubules. Microtubules themselves undergo both axial translatory (“sliding”) and lateral “zipping and unzipping” movements that have been suggested to occur during mitosis and other biological processes.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970010303
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  • 8
    Electronic Resource
    Electronic Resource
    The identification and localization of actin and actin-like filaments in lactating guinea pig mammary gland alveolar cells (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 329-347 
    Details
    ISSN: 0886-1544
    Keywords: actin ; microfilaments ; heavy meromyosin ; mammary gland ; secretion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cytochalasin B, a microfilament-altering drug, inhibits lactose synthesis in lactating guinea pig mammary gland [Biochim. Biophys. Acta 392:20, 1975] but not primarily by inhibiting glucose transport [Eur. J. Cell Biol. 20:150, 1979]. In order to study the possible role of microfilaments in lactose synthesis and secretion, we isolated both the alveolar (milk-secreting) and myoepithelial (contractile) cells from lactating mammary gland. Light microscopy shows that the alveolar cell fraction (viability approximately 71%) is homogenous and that the cells retain strong polarity of secretory structures in the apical region. Two proteins were extracted from the alveolar cell fraction. One (mol wt 42,000) comigrates with skeletal muscle actin on SDS-PAGE gels. The other, a high-molecular-weight (180,000) protein (HMWP) may be analogous to actin-binding protein or clathrin. An extract from the myoepithelial cell fraction also contains a protein that comigrates with actin but no HMWP. Whole tissue extract contains the 42K protein, and a 185K HMWP. Examination of the alveolar cell extract by electron microscopic (EM) negative staining revealed meshworks of multistranded, interconnecting filaments, with attached globular structures (100-200 A) (possibly the HMWP) and single filaments (40-60 A diameter) branching off. To localize these filamentous structures in situ, whole tissue was glycerinated and incubated with rabbit skeletal muscle heavy meromyosin (HMM). Masses of filaments in myoepithelial cells served as convenient standards for HMM decoration. Decorated filaments have cross-arms or projections, unlike the narrow, smooth filaments of control tissue. Decorated filaments in alveolar cells are located beneath the plasma membrane, in close association with secretory vacuoles, and near the Golgi apparatus; filaments near the latter two are often oriented perpendicular to the plasma membrane. Microvesicles are embedded in meshworks under the plasmalemma and near the Golgi apparatus. Intermediate-sized (85-115 A diameter), non-decorated filaments diverge from the meshworks of decorated filaments. Microvesicles are associated with intermediate-sized filaments as well. The association of actin-like filaments with secretory vacuoles and microvesicles and their location in areas of the cell concerned with biosynthetic activities suggest a possible function in the intracellular transport of secretory products.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010305
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  • 9
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    Intercellular bridges in the embryo of the atlantic squid, loligo pealei. II: Formation of the bridge (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 455-468 
    Details
    ISSN: 0886-1544
    Keywords: intercellular bridge ; intercellular communication ; cytokinesis ; squid ; ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Incomplete cytokinesis followed by the disappearance of the midbody and spindle remnant results in intercellular bridges between the cells of the blastoderm of the squid embryo. An electron microscope study of the morphology of the stages of development of the intercellular bridge is presented. Cytokinesis ceased as the furrow base reached a diameter slightly larger than the midbody. As furrowing stopped, a dense material accumulated to form a cylindrical sheath 50 nm thick, lining the inner surface of the furrow base. Proteolytic enzymes showed this material to have a significant protein component. As the midbody broke down, vesicles lined the inner surface of the bridge sheath. In this configuration, there was cyto-plasmic continuity between the cells, and organelles appeared to pass through the bridge.The intercellular bridge could become temporarily closed. Vesicles entered the channel and fused with the vesicles lining the inner surface of the sheath. The vesicles enlarged until the channel became occluded with a series of transverse cisternae, the edges of which were embedded in the material of the sheath. When the bridge reopened, the transverse cisterna appeared to dissociate from the sheath, move out of the channel, and break down. Occasionally bridges were seen in which the bridge wall appeared distorted into lobes. It is suggested that such bridges might be in the porcess of breaking down, resulting in the final separation of the cells.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010406
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  • 10
    Electronic Resource
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    Nucleated assembly of mitotic microtubules in living PTK2 cells after release from nocodazole treatment (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 469-483 
    Details
    ISSN: 0886-1544
    Keywords: microtubules ; nucleation ; mitosis ; nocodazole ; immunocytochemistry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The reassembly of microtubules is described in mitotic cells after release from nocodazole-induced block. The formation of microtubules was followed by light microscopic immunocytochemical staining using the PAP method, combined with to-luidine blue staining of the chromatin. The light microscopic observations on whole cells were compared with ultrastructural observations on thin sections. This step is essential to ascertain complete destruction of microtubules during the nocodazole treatment and to correlate immunocytochemical staining with the presence of microtubules.Removal of nocodazole (10 or 1 μg/ml) after a sufficiently long incubation to induce a complete disappearance of microtubules resulted in the appearance of tubulin staining specifically associated with the centromeres and with one or two isolated points in the cytoplasm. Electron microscopy confirmed that the staining was due to the massive accumulation of small microtubules at the kinetochores and centrosomes. Kinetochore nucleation was seen only in association with condensed metaphase-stage chromosomes and not with the less-condensed prophase chromosomes.In a second type of experiment cells were allowed to enter mitosis in the presence of an incompletely active concentration of nocodazole (0.1 μg/ml). The construction of the mitotic spindle was arrested; however, short microtubules were assembled at the kinetochores and centrosomes.These experiments demonstrate that in living mitotic PTK2 cells the kinetochores, as well as the centrosomes, exert a nucleating action on tubulin assembly.The further elongation of microtubules after removal of nocodazole was seen to occur preferentially along axes between the centrosomes and the kinetochores. This resulted in the construction of normal metaphases that evolved through anaphase and telophase. We have attempted to formulate a hypothesis that may explain the oriented assembly that seems to be essential in the construction of the spindle.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010407
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  • 11
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    Invited review: The role of nucleotide triphosphate in actin and tubulin assembly and function (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 485-497 
    Details
    ISSN: 0886-1544
    Keywords: actin ; tubulin ; nucleotides ; polymerization ; microfilaments ; microtubules ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Both actin and tubulin, the major proteins of the cytoskeleton, bind nucleotide triphosphate (NTP) and exhibit the phenomenon of “polymerization-coupled” NTP hydrolysis. In this report I review the nature of polymerization-coupled NTP hydrolysis, and its possible role in the cellular function of actin and tubulin. Polymerization-coupled hydrolysis may be viewed as simply reflecting differences in the NTPase activity of free subunit as compared to polymer. Making assumptions concerning the values of various rate constants, it is possible to write expressions for the effects of NTP hydrolysis on the kinetics of polymerization. The role of NTP hydrolysis may be viewed in at least three different ways: (1) Hydrolysis alters the kinetics of assembly and disassembly. This leads to a consideration of the role of subunit flow in microtubule and microfilament function. (2) Hydrolysis is an essentially irreversible step that separates the assembly and disassembly reactions. This suggests a role of NTP in the regulation of polymer content during cellular cycles of assembly and disassembly. (3) NTP may allow transient stabilization of intersubunit bonds. This suggests a role of NTP in nucleation and possible regulation of nonequilibrium states of assembly.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970010408
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  • 12
    Electronic Resource
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    Dynein binding to microtubules containing microtubule-associated proteins (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 499-515 
    Details
    ISSN: 0886-1544
    Keywords: dynein ; tubulin ; axonemes ; microtubules ; microtubule-associated proteins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Microtubule-associated proteins (MAPs), isolated from brain tubulin, bound to and saturated outer fibers of Chlamydomonas flagella. MAPs present on these microtubules prevented the subsequent recombination of dynein. MAPs also bound to intact axonemes and thus did not specifically bind to the dynein binding sites on the A subfiber. A molar ratio of 1 mole MAP2 per 27 moles tubulin dimers at saturation of the outer fibers with MAP2 suggested that MAPs could effectively interfere with dynein recombination only if the MAPs were near the dynein binding sites to sterically prevent binding. However, electron microscopic observations indicated that MAPs were not localized but, instead, were dispersed around the outer fibers. In addition, MAP2 present at saturating amounts on in vitro assembled brain microtubules had no significant effect on dynein binding. Dynein-decorated microtubules contained clusters of arms suggesting that there may be cooperative interaction between the arms during dynein binding. Because the A subfiber of axonemes contains sites to which dynein preferentially attaches, MAPs may prevent recombination by interfering with cooperative binding to these specific sites. Dynein presumably binds with equal affinity to any protofilament on in vitro assembled microtubules, and, therefore, the MAPs may not be capable of effectively interfering with cooperative binding of dynein to these microtubules.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970010409
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  • 13
    Electronic Resource
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    Distribution of tubulin and actin in neurites and growth cones of differentiating nerve cells (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 167-178 
    Details
    ISSN: 0886-1544
    Keywords: nerve growth ; actin ; tubulin ; antibodies ; immunofluorescence ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Embryonic chick nerve cells, from dissociated dorsal root ganglia, were cultured on polylysine substrata and examined for tubulin and actin distribution by indirect immunofluorescence.Antibodies generated against chick brain tubulin produced specific fluorescence in growth cones, neurites, and cell bodies without revealing distribution differences or substructure in the nerve cells. However, at reduced antitubulin concentrations, differences were resolved. Tubulin fluorescence remained uniform and intense in neurites and cell bodies, but exhibited reduced intensity and patterning in growth cones. Nonneuronal cells in the reduced intensity and patterning in growth cones. Nonneuronal cells in the cultures served as controls for typical cytoplasmic tubulin fluorescence distribution. Straining controls demonstrated that fluorescence resulted from tubulin-antitubulin binding.Analogous studies, using antibodies generated against chick brain actin, demonstrated distribution differences at reduced antiactin concentrations, including “hot spots” of intense fluorescence in growth cones and a paucity of fluorescence in neurites.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970010202
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  • 14
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    Does the geometric design of centrioles imply their function? (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 237-245 
    Details
    ISSN: 0886-1544
    Keywords: centrioles ; symmetry ; triplet blades ; thermal fluctuations ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The paper suggests several principles of construction of a microscopically small device for locating the directions of signal sources in microscopic dimensions. It appears that the simplest and smallest device that is compatible with the scrambling influence of thermal fluctuations as are demonstrated by Brownian motion is a pair of cylinders oriented at right angles to each other. Nine equally spaced blades run in a pitched fashion along the mantle of each cylinder. The blades have a concave cross-section and bend around the circumference of the cylinder in a certain rotational pattern. Considering the striking similarity of this hypothetical device with centrioles, the paper puts forward the conjecture that centrioles locate the direction of hypothetical signals inside cells.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970010206
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  • 15
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    Microtubule sliding in cilia of the rabbit trachea and oviduct (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 247-260 
    Details
    ISSN: 0886-1544
    Keywords: cilia ; trachea ; ATP-reactivation ; ciliary activity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Evidence for active sliding of microtubules during ciliary activity has been demonstrated in a number of organisms: sea urchin sperm flagella, protozoan cilia, and mollusc gill cilia. Although there is evidence that active sliding also occurs in mammalian sperm flagella, there is little or no information on whether active sliding of microtubules also occurs in the short (5-μm) cilia of the mammalian trachea or oviduct. Since these cilia are important in tracheobronchial clearance and ovum transport, respectively, it has been important to demonstrate that microtubule sliding is also involved in the activity of somatic cilia. Ciliated apical portions (cortices) and cilia were isolated from rabbit trachea and oviduct, using Triton X-100 to demembranate the cilia. Most of the ciliated cortices reactivated upon addition of ATP, whereas isolated cilia reactivated to a lesser extent. When preparations of cilia were digested with trypsin before or after ATP addition, disintegration of axonemal doublets occurred with about the same frequency as reactivation. These events were recorded using Nomarski optics and dark-field microscopy. When isolated cilia which had been digested by trypsin and exposed to ATP were also prepared for electron microscopy by negative staining, telescoping of doublet microtubules from axonemes could be shown. These results demonstrate that mammalian somatic ciliary doublet microtubules actively slide in a manner similar to that described for invertebrate cilia.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970010207
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  • 16
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    Meeting report. American society for cell biology (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 269-272 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010209
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  • 17
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    Chemotaxis in Tetrahymena thermophila (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 261-268 
    Details
    ISSN: 0886-1544
    Keywords: Tetrahymena ; chemotaxis ; temporal-gradient sensing ; modulation of turning frequency ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The motility pattern of Tetrahymena thermophila in a homogeneous attractant field consists of successive “runs” and “turns.” The turning frequency decreases or increases upon an abrupt increase in attractant or repellent concentration, respectively. The dose-response curve for leucine and methionine yields a saturation curve with half maximum modulation of the turning frequency at a concentration of 15 μM and 2 μM, respectively. The turning frequency is modulated at a threshold concentration of 0.02 μM and 0.50 μM for leucine and methionine, respectively. The decrease (increase) in turning frequency in the presence of an attractant (repellent) jump reverts to prestimulus frequency in a time proportional to the concentration jump. Hence, Tetrahymena seem to employ temporal-gradient sensing for chemotaxis. Spatial-gradient taxis is thus exerted by random walk, which is biased in the direction of the gradient.
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    Announcement (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 273-273 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010210
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010301
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    Video-enhanced contrast polarization (AVEC-POL) microscopy: A new method applied to the detection of birefringence in the motile reticulopodial network of allogromia laticollaris (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 275-289 
    Details
    ISSN: 0886-1544
    Keywords: videomicroscopy ; polarization microscopy ; streaming ; reticulopodial motility ; Allogromia ; microtubules ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A new method is described for recording rapid processes of cell motility in polarized light. The Allen video-enhanced contrast (AVEC-POL) method of polarization microscopy achieves significant improvements in resolution, contrast, and the visibility of fine detail by a combination of novel adjustments to a standard (unrectified) polarizing microscope and video camera. Using the full working aperture of a high-power planapochromatic objective lens and compensator setting of λ/9-λ/4, visible images appear lacking in contrast. However, the same images viewed with an appropriate video camera equipped with an electronic offset adjustment can be made to appear with as much contrast as desired, revealing a significantly greater amount of fine detail in the image than can be seen by high extinction visual microscopy alone. At bias retardations between one-ninth and one-quarter wave, the diffraction anomaly observed near extinction disappears. Consequently, polarizing rectifiers are not required with the AVEC-POL method, and images previously requiring photographic exposures of around 20 seconds are sufficiently bright to be registered on the video monitor in 1/60 second. Using an intensity monitor, quantitative measurements of cellular birefringence can be retrieved from live or videotaped images displaying a linear relationship between contrast and phase retardation due to birefringence. The AVEC-POL method also renders accessible to polarized light analysis a number of objects that scatter or depolarize too much light to be studied by high extinction methods. The method is demonstrated on model objects and applied to the highly motile reticulopodial network of Allogromia laticollaris. Rapid motion in close association with microtubules can now be analyzed in greater detail at a significant reduction in the cost of recording.
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    URL: http://dx.doi.org/10.1002/cm.970010302
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    The mechanochemical cycle of the dynein arm (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 303-327 
    Details
    ISSN: 0886-1544
    Keywords: cilia ; microtubules ; ATPase ; vanadate ; geometry of sliding ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A dynein arm attachment cycle produces sliding between adjacent doublet microtubules (N and N + 1) of cilia. In intact axonemes, in the absence of ATP, almost all arms appear attached at both ends (rigor). When ATP is added, most arms detach from doublet N + 1. In ATP and vanadate, the arms do not return to rigor, suggesting that ATP hydrolysis is required for re-extension and reattachment of the dynein arm, but not for detachment. Using solutions containing dynein to decorate dynein-less axonemal doublets, we confirm this interpretation. In the absence of ATP, both sides of each doublet decorate with arms. Addition of ATP, ATP and vanadate or AMP-PNP causes immediate arm detachment, but only in the first instance, where extensive ATP hydrolysis can occur, does decoration eventually reappear. Dynein decorates heterologous axonemal doublets and brain microtubules, as well as homologous doublets, suggesting that this mechanochemical cycle may have general applicability in microtubule-based cell motility.
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    Simultaneous oscillations of Ca2+ efflux and tension generation in the permealized plasmodial strand of physarum (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 433-443 
    Details
    ISSN: 0886-1544
    Keywords: Physarum ; acellular slime mold ; calcium ion ; calcium-ionophore ; cytoplasmic contraction ; oscillation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Calcium is now generally thought to play a key role in regulating a variety of cellular movements. When the plasmodium of Physarum polycephalum was treated with the calcium-ionophore A23187 or the quasi-ionophore amphotericin B, Ca2+ leaked out. Ca2+ efflux into the ambient solution from the plasmodial strand segment was measured by the luminescence of a photoprotein aequorin, and the tensile force production was recorded simultaneously. Ca2+ efflux oscillated with the same period as the cycle of tension generation in the strand, but the phase of cyclic changes in Ca2+ efflux was opposite to that of tension generation. That is, Ca2+ efflux fell in the increasing tension phase and rose in the decreasing tension phase. Cyclic changes in efflux of Ca2+ are provisionally interpreted as reflecting corresponding changes in concentrations of free Ca2+ in the cytoplasm.
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    Taxol induces microtubule assembly at low temperature (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 445-454 
    Details
    ISSN: 0886-1544
    Keywords: taxol ; microtubules ; polymerization ; tubulin ; mitotic inhibitor ; protein self-assembly ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Dissociated bovine brain microtubule protein has been shown to reassemble at 0°C in the presence of the drug taxol. Tubulin polymerization was monitored both by electron microscopy of the polymeric structures and by incorporation of tritiated GTP into filterable polymeric structures. Most of the labeled guanine nucleotide uptake into tubulin polymeric structures occurred in the first 30 minutes of incubation with the drug. The initial polymerization event results in the formation of protofilamentous tubulin ribbons. The first microtubules were noted after 1 hour of incubation with the drug. After 20 hours of incubation at 0°C with taxol, the bulk of the polymerized tubulin appeared to be in the form of microtubules. Cold-stable tubulin rings with a mean diameter of 34 nm were present in the reaction mixture before the addition of taxol and throughout the 20-hour incubation. Most of the rings were apparantly not involved in the taxol-induced microtubule assembly. The results are consistant with a model whereby taxol induces an initial formation of protofilamentous ribbon structures, mostly from free tubulin dimers, and a slower subsequent folding of the ribbon structures into microtubules.
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    The incorporation of actin and fascin into the cytoskeleton of filopodial sea urchin coelomocytes (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 179-192 
    Details
    ISSN: 0886-1544
    Keywords: actin ; echinoderm ; fascin ; filopodia ; actin cross-linking protein ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Echinoderm coelomocytes transform from petaloid cells with large motile lamellipodia to filopodial forms. During this morphological transformation, actin filaments extensively reorganize from a random meshwork into tight bundles, which become the skeletons or cores of the filopodia. Antibody localization procedures show that fascin, a 58,000 dalton actin cross-linking protein, becomes incorporated into the filament bundles as they form. Isolated filopodial cores have a pronounced transverse striping pattern, which has been previously identified with fascin crosslinks, and gel electrophoresis identifies a protein in the cores that co-migrates with purified egg fascin. A few of the core fragments also have a distinctive “cap,” which we presume is the membrane insertion site for actin filaments.We have developed a radioimmunoassay for fascin and have used it to study the redistribution of this protein during transformation. Data from the assay indicate that fascin constitutes about 5% of the total cell protein and that substantially more fascin, approximately 1.5-2 times more, is found in the Triton-insoluble cytoskeletons of the filopodial cells than in the petaloid cells. Actin, measured by the DNAase I inhibition assay accounts for approximately 10% of the total cell protein. Approximately 65% of this actin is in a soluble non-filamentous form in the petaloid cells. Our results show that actin polymerization must occur during the cell shape change, since we find approximately 25% more actin in the filopodial cytoskeleton than in the petaloid cytoskeleton. The results show a preferential incorporation of fascin into the cytoskeleton as the cells form filopodia.
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    URL: http://dx.doi.org/10.1002/cm.970010203
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    Ultrastructural studies of a polygonal myofilament network in cultured rat aortic smooth muscle cells (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 193-203 
    Details
    ISSN: 0886-1544
    Keywords: polygonal network ; rat aortic smooth muscle cell ; cell culture ; electron microscopy ; amino acid analysis ; elastin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cultured rat aortic smooth muscle cells (SMC) were examined by electron microscopy and found to contain polygonal networks of 75 A° thin myofilament bundles. The cells also had large bundles of longitudinally aligned thin myofilaments with periodically spaced dense bodies. Abundant plasmalemmal vesicles were present at the cell periphery, and the cells were connected by desmosomes. Intercellular spaces contained sparse amounts of elastic fibers, a material generally present in SMC cultures. Analyses of amino acids by automated column-chromatography showed that isodesmosine and desmosine, two amino acid residues unique for elastin, were present. Accordingly, it was concluded that polygonal networks, previously detected solely in cultured nonmuscle cells, were present in SMC.Other findings suggest (1) a change in myofilament arrangement takes place during cell migration, and (2) rat aortic SMC grown in tissue culture flasks is an important experimental tool in the study of cell motility since such myofilament rearrangements were observed to occur up to fourteen days in first passage.
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    Motion of polymorphonuclear leukocytes: Theory of receptor redistribution and the frictional force on a moving cell (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 205-235 
    Details
    ISSN: 0886-1544
    Keywords: capping of receptors ; cell locomotion ; cell-surface interactions ; frictional force ; membrane flow ; polymorphonuclear leukocytes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: As a cell moves over a surface, the distribution of membrane proteins that adhere to the surface will be changed relative to the distribution of these molecules on a static cell. Observations of this redistribution offer, in principle, evidence as to the mechanisms of membrane dynamics during cell locomotion. Toward extracting such information we present and analyze a mathematical model of receptor transport in the membrane by diffusion and convection, as affected by the making and breaking of the bonds between the receptors and the surface as the cell moves.We show that the disruption of receptor-surface bonds at the tail of the cell provides a mechanism by which the frictional force opposing a cell's motion is exerted, and calculate the magnitude of this force as a function of cell velocity. Assuming this to be the major contribution to the frictional force, we show that when the shear force on a cell is above a critical value it is no longer possible for the cell to slide across the surface. For such large forces, it is still possible for the cell to roll; alternatively the cell can be torn free of the surface.Our analysis of existing data on movement of polymorphonuclear leukocytes indicates that cell motion is not accompanied by a bulk flow of membrane from the front to the back of the cell. The data also indicate that cells do not tend to roll as they move over a surface under normal conditions. The data are most consistent with a model where the membrane as a whole is stationary but where receptors that bind to the surface become coupled to sub-membrane contractile proteins.
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    Quantitative studies on polarization optical properties of living cells III: Cortical birefringence of the dividing sea urchin egg (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 387-397 
    Details
    ISSN: 0886-1544
    Keywords: birefringence ; polarizing microscope ; sea urchin egg ; cortex ; mitosis ; cleavage ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Birefringence (BR) at the cell surface of fertilized eggs of the sand-dollar, Clypeaster japonicus, during mitosis and cleavage was determined with a photoelectric BR detection apparatus [Hiramoto et al, 1981a]. The cortex of about 2 μm thickness is birefringent positive with respect to the normal to the cell surface. The hyaline layer is negatively birefringent. The halo-layer consisting of a row of microvilli surrounding the egg is positively birefringent in normal Ca-free sea water, while it is negatively birefringent in Ca-free sea water with high refractive index. The BR of the cortex gradually increases over the entire surface during mitosis until the onset of cleavage. The BR of the cortex at the polar region reaches a maximum shortly after the onset of cleavage and then decreases, while the BR of the cortex at the equatorial region begins to decrease shortly before the onset of cleavage, reaches a minimum shortly after the cleavage starts, and then increases again as the cleavage furrow advances. The coefficient of birefringence of the cortex is about 2.5 × 10-5 at the maximum. The BR change of the cortex during mitosis and cleavage is interpreted as a passive deformation caused by the constriction of the contractile ring as well as an active structural change of the cortex occurring in the dividing cell.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010401
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    The distribution of 10nm filaments and microtubules in endothelial cells during mitosis: Double-label immunofluorescence study (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 417-431 
    Details
    ISSN: 0886-1544
    Keywords: spindle poles ; centrioles ; cell center ; scaffold ; electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: I have used fluorescence microscopy and antibodies to 10nm filaments and tubulin labelled with contrasting fluorochromes to compare the distribution of these proteins in endothelial cells during cell division. During interphase the two filament systems have entirely different distributions: The bulk of the 10nm filaments form a ring that surrounds the cell center and nucleus and remains parallel to the substrate, while the microtubules radiate from the cell center to the cell's border. When the mitotic spindle replaces the radial microtubule pattern in mitosis, the spindle poles remain within - and in close proximity to - the ring of 10nm filaments. This was confirmed by electron microscopy which showed the ring and centrioles in the same plane separated by a distance of 300-400 nm.
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    Abnormal myosin heavy chain variant associated with avian muscular dystrophy (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 399-416 
    Details
    ISSN: 0886-1544
    Keywords: myosin heavy chain ; avian muscular dystrophy ; adult and embryonic fast white fibers ; slow red fiber ; rod ; subfragment-1 ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Avian muscular dystrophy is characterized by the degeneration of fast white skeletal muscle fibers, with onset during development. Using a one-dimensional peptide mapping technique, we have detected two forms of the myosin heavy chain in the fast white fibers of adult domestic chickens, one form characteristic of birds homozygous for muscular dystrophy, the other of their normal controls. Four dystrophic strains carrying the same gene for muscular dystrophy were examined.No differences were detected in the embryonic heavy chain peptide maps of normal and dystrophic chickens, consistent with the developmental onset of the condition. Differences were also absent from the peptide maps of heavy chains from slow red fibers, which are unaffected in dystrophy. No dystrophy-specific peptide map differences were detected in the three light chains. Analysis of peptide maps of rod and the heavy chain component of subfragment-1 from normal and dystrophic heavy chains indicates the presence of amino acid sequence differences in the two proteins.
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    The role of the extracellular matrix in cell motility in fibroblast aggregates (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 99-112 
    Details
    ISSN: 0886-1544
    Keywords: cell motility ; extracellular matrix ; collagen ; glycosaminogly cans ; collagenase ; hyaluronidase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effect of specific components of the extracellular matrix on the motility of tissue cells was studied using organ-cultured aggregates of embryonic fibroblasts. Spherical aggregates of chick embryo heart and skin fibroblasts were fused with [3H]-thymidine-labeled aggregates of the identical cell type. The movement of labeled cells into the unlabeled partner aggregate served as an estimate of cell motility in the cultured tissue-like aggregates. Collagenase treatment decreased the collagen content of heart fibroblast aggregates and increased cell motility; ascorbic acid treatment increased the collagen content of skin fibroblast aggregates and decreased cell motility. Reduction of the glycosaminoglycan content with testicular hyaluronidase had no measurable effect on cell motility in heart fibroblast aggregates.
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    Identification of genetic elements associated with muscle structure in the nematode caenorhabditis elegans (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 73-97 
    Details
    ISSN: 0886-1544
    Keywords: nematodes ; muscle structure ; mutants ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A search for new mutants with altered body-wall muscle cell structure has been undertaken in the nematode C elegans. One-hundred seventeen mutants were isolated after mutagenesis with ethyl methanesulfonate or ultraviolet light, enrichment by a motility-requiring test, and screening by polarized light microscopy; 102 of these mutants were in ten previously established genes, whereas 15 mutants permitted the identification of seven new complementation groups in C elegans. Two of the new genes map on linkage group I (unc-94 and unc-95) and four genes are sex linked (unc-96, unc-97, unc-98, and unc-99). One complementation group (unc-100) could not be mapped because of the special characteristics of its cohort mutants. Representative mutants of the mapped genes were examined by polarized light and electron microscopy. All of the mutants exhibit disruptions of the normal A and I band organization of thick and thin filaments. Several of the mutants produce collections of thin filament-like structures. In one of these cases, HE177 demonstrated collections of somewhat wider, intermediate-sized filaments as well, and the HE195 mutant produces paracrystalline aggregates of thin filaments amidst looser arrangements of similar structures. The mutants in newly identified genes, as well as the new mutants in previously established genetic loci, have promise as tools in the study of myofibrillar assembly and function. Among the 22 complementation groups associated with body-wall structure in C elegans, it is likely that some genes code for regulatory and morphogenetic functions in addition to the well-studied structural, contractile, and calcium-associated proteins in muscle.
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    Tubulin content and synthesis in differentiating drosophila cells in culture (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 113-129 
    Details
    ISSN: 0886-1544
    Keywords: tubulin ; Drosophila ; β-ecdysterne ; differentiating ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Drosophila Kc cells exposed to physiological doses of the moulting hormone, β-ecdysone, elongate, become motile, and subsequently aggregate. This pattern of morphogenesis was found to require the assembly of a microtubular cytoskeleton. Tubulin content was significantly increased in hormone-treated cells when compared to controls, as measured by a 3H-colchicine-binding assay. However, determinations of rates of tubulin synthesis and breakdown revealed no difference between control and hormone-treated cells for either parameter. When tubulin content was assayed by methods that do not depend on colchicine-binding activity, no difference between hormone-treated and control cells was observed. These results are discussed in terms of a model in which β-ecdysone affects the distribution of tubulin in “assembly-active” and “assembly-inactive” pools.
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    Meeting report (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 159-162 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010112
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    The formation and elongation of filopodia during transformation of sea urchin coelomocytes (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 131-140 
    Details
    ISSN: 0886-1544
    Keywords: sea urchin coelomocytes ; motility ; filopodial formation and elongation ; ciné film analysis ; scanning electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Sea urchin coelomocytes were examined during their morphological transformation from petaloid to filopodial forms by scanning electron microscopy and ciné film analysis. Petaloid coelomocytes have a variable morphology but, in general, consist of numerous thin sheets of cytoplasm, the petals, arranged in three dimensions around a central nuclear region. The transition to the filopodial form can occur in either substrate-attached or suspended cells and begins with the formation of several microspikes at the edge of each petal. These become more apparent as the cytoplasm between each microspike/filopodium is retracted centripetally. Concomitantly, the diameter of the flattened cell is increased by as much as twofold as the filopodia actively lengthen at a uniform, average rate of 0.5 μm/minute. The transformation process requires ca 15 minutes and is complete when the cell diameter no longer increases. These filopodia are functionally distinct from the passively produced retraction fibers observed in cultured mammalian cells. The formation of filopodia is biphasic and includes both a cytoplasmic retraction phase and an active extension phase.
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    Invited review: Guidance cue patterns and cell migration in muiticeliuiar organisms (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 141-157 
    Details
    ISSN: 0886-1544
    Keywords: axon guidance ; chemotaxis ; haptotaxis substrate pathways ; development ; pattern biology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In multicellular organisms, guidance cues are either diffusible molecules or cellular or extracellular surfaces that are found in reproducible locations and that orient migrating cells and cell processes. The pattern of the guidance cues usually determines the complex in vivo migration routes of motile cells and cell processes. Within organisms, guidance cues are found to be organized in two general patterns: (a) broad gradients - such as diffuse chemotactic gradients; (b) discrete routes (substrate pathways) - such as chemotactic gradients confined to long channels, and such as the axon surface which represents a long specific highway for migrating Schwann cells.
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    Announcement (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 163-163 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010113
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    Statement of purpose (1980)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1980), S. 167-167 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010114
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010201
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    Calcium-induced change in form of demembranated sea urchin sperm flagella immobilized by vanadate (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 349-362 
    Details
    ISSN: 0886-1544
    Keywords: Ca2+ ; flagella ; symmetry ; vanadate ; spermatozoa ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Increased Ca2+ concentration causes a reversible increase in asymmetry of the flagellar bending waves of “potentially symmetric” demembranated sea urchin spermatozoa. When these flagella are immobilized with 5 μM vanadate, increased Ca2+ concentration causes a reversible increase in the total bend angle between the tip and the base of the immobilized flagella. These effects of Ca2+, and the movement which can be activated by CaATP2-, can be inhibited by vanadate, but in both cases, high concentrations of vanadate, of the order of 100 μM, are required. These observations suggest that ATP, possibly in the form of CaATP2-, is required for the Ca2+-induced change in shape of the flagella, but other observations suggest that the magnitudes of asymmetry and total bend angle are more closely related to Ca2+ concentration than to CaATP2- concentration.
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    Effects of Triton-extraction conditions on beat symmetry of sea urchin sperm flagella (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 363-370 
    Details
    ISSN: 0886-1544
    Keywords: Ca2+ ; Mg2+ ; symmetry ; flagella ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Potentially asymmetric spermatozoa are obtained when spermatozoa are demembranated in the presence of a low Ca2+/Mg2+ ion concentration ratio. They swim with asymmetric bending waves even when reactivated at low Ca2+ concentrations, and become more asymmetric when Ca2+ is increased. Potentially symmetric spermatozoa, which swim with symmetric bending waves at low Ca2+ and become asymmetric as the Ca2+ is increased, can be obtained by exposing the flagella to a high Ca2+/Mg2+ ratio, either during or subsequent to demembranation. The rate of this conversion is an increasing function of temperature and Triton concentration. Potentially symmetric spermatozoa can be reconverted to potential asymmetry, if the exposure to high Ca2+/Mg2+ is brief, and is terminated by addition of EGTA and Mg2+ before diluting the spermatozoa. The conversion to potential symmetry may involve removal of a labile component from the axoneme.
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    The motion mechanics of Nitella filaments (Cytoplasmic streaming): Their imitation in detail by screw-mechanical models (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 371-385 
    Details
    ISSN: 0886-1544
    Keywords: rotating filaments ; cytoplasmic streaming ; Nitella ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Our knowledge about the actin-containing characean filaments on the basis of light and electron microscopical investigations is reviewed. Dynamic filamentous networks, known already from isolated droplets, were detected in Nitella rhizoidal cells using light microscopical techniques. Earlier light microscopic observations in cytoplasmic droplets are confirmed and complemented by new model experiments with rotating helices. The motile phenomena occurring at the filament bundles (ring formation, wave propagation, particle translocation, net dynamics, rolling motions, formation of side arms) can, in this way, be imitated in detail. Thus, the concept of cytoplasmic streaming as a translocation along bundles of rapidly rotating helical filaments is supported. In order to explain unidirectional cytoplasmic streaming, a periodic winding up and unwinding of fine filaments is postulated by which ions are periodically bound and displaced. The formation of side arms which is favored during unwinding results in a screw-mechanical different behavior of the filaments in the two directions of rotation and therefore causes permanent particle transport in one direction.
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    Origin and migration of primordial germ cells in mammals (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 333-362 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120040407
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    Acquisition of meiotic competence in the rat: Role of gonadotropin and estrogen (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 463-472 
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    ISSN: 0148-7280
    Keywords: oocyte ; meiotic competence ; estrogen ; PMSG ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Oocytes were removed from the follicles of rats at 15 to 31 days of age, and their ability to resume meiosis (“meiotic competence”) in vitro was correlated with their diameter and the stage of follicular development. The majority of oocytes explanted on day 15 did not resume meiosis when placed in culture, but the percentage of competent oocytes increased from 14.1% ± 3.0% on day 20 to 67.6% ± 3.3% on day 26 of age. This ability to resume maturation correlated well (r = 0.98) with the increase in diameter of oocytes and coincided with the development of antral follicles.Hypophysectomy on day 15 of age, but not on day 20, reduced the percentage (P 〈 0.001) and number (P 〈 0.001) of competent oocytes and was accompanied by a reduction in diameter of oocytes. Treatment with PMSG or E2 increased the number (P 〈 0.001) and percentage (P 〈 0.001) of competent oocytes. These results suggest that the ability of oocytes to mature in vitro is dependent upon stimulation by gonadotropins and that this action of gonadotropin may be mediated by production of estrogen within the follicles.
    Additional Material: 6 Ill.
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    Biology of the ovary. Vol. 2 of developments in obstetrics and gynecology. P. M. Motta and E.S.E. Hafez, eds., Martinus Nijhoff Publishers, The Hague, 1980. 26 chapters, illustrations, index. 344 pages. $86.85 (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 485-486 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040511
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    Animal models for research on contraception and fertility. Nancy J. Alexander, ed., Harper and Row, Hagerstown, 1979. 45 chapters, 186 illustrations, index. 587 pages. $22.50 (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 486-486 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040512
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    Other books received (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 486-486 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040513
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    Effect of FSH and HCG on progesterone secretion by cultured oocyte-cumulus complexes and granulosa cells from porcine antral follicles: Influence of follicular development (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 473-483 
    Details
    ISSN: 0148-7280
    Keywords: oocyte-cumulus complex ; granulosa cell ; monolayer formation ; LH/FSH effects on progesterone ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Oocyte-cumulus complexes and granulosa cells were harvested from small (1-2 mm), medium (3-5 mm), and large (6-12 mm) porcine antral follicles and cultured for 2 and 3 days. The effects of various doses of purified hCG and human FSH on progesterone secretion and monolayer formation were examined. After a 2-day culture period it was found that FSH was more effective in stimulation of progesterone secretion by cultured oocyte-cumulus complexes than in granulosa cells harvested from small follicles (P 〈 0.01), whereas hCG was more effective in stimulating progesterone secretion in granulosa cells than in oocytecumulus complexes harvested from large follicles. In contrast, after a 3-day culture period, granulosa cells secreted more progesterone compared to oocytecumulus complexes under control conditions or in the presence of hCG or FSH. After 3 days both FSH and hCG stimulated progesterone secretion by oocytecumulus complexes and granulosa cells; however, the hormone effect was greater upon granulosa cells than oocyte-cumulus complexes. After 3 days of culture in the case of both follicular cell types, there was a greater response to FSH in the case of cells harvested from small compared to large follicles. The reverse was true in the case of hCG responsiveness.Monolayer formation ability of oocyte-cumulus complexes was greater in the case of complexes harvested from small and medium than complexes harvested from large follicles. Addition of hCG to the cultures led to a dose-dependent decrease in monolayer formation by oocyte-cumulus complexes harvested from all sizes of follicles.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981) 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040601
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    Evidence for nonmuscle myosin in bovine ejaculated spermatozoa (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 499-506 
    Details
    ISSN: 0148-7280
    Keywords: sperm ; nonmuscle myosin ; affinity column ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mammalian spermatozoa contain nonmuscle actin and many of the components of regulatory systems thought to be involved in nonmuscle actin-myosin function. An actin-stimulated adenosine triphosphate hydrolase (ATPase) activity has been fractionated from bovine ejaculated spermatozoa by immobilized-actin affinity chromatography. The actinstimulated ATPase activity has a specific activity (0.04 ± 0.02 mM phosphate released/min/mg protein) similar to nonmuscle myosins from other mammalian cells and tissues, but it does not have appreciable K+-EDTA ATPase activity. The sperm actin-myosin may function in sperm morphogenesis in the seminiferous tubule, in capacitated spermatozoa undergoing an acrosome reaction, or in decondensation of the sperm nucleus after fertilization.
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    URL: http://dx.doi.org/10.1002/mrd.1120040603
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    Stimulation of hamster sperm capacitation and acrosome reaction in vitro by glucose and lactate and inhibition by the glycolytic inhibitor α-chlorohydrin (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 515-523 
    Details
    ISSN: 0148-7280
    Keywords: glucose ; glycolysis ; lactate ; sperm ; capacitation ; acrosome reactions ; α-chlorohydrin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Studies were made of the effects of D(+)-glucose, L-lactate and pyruvate on in vitro capacitation and acrosome reactions (AR) of hamster sperm using a more “defined” medium that that used in previous similar studies. In the absence of glucose or lactate, sperm underwent very few AR and activation (whiplash-like motility characteristic of capacitated hamster sperm) was reduced compared to those events in sperm preincubated in the presence of glucose plus lactate plus pyruvate. Glucose and pyruvate supported more AR than glucose alone, but less than glucose, lactate, and pyruvate. The glycolytic inhibitor α-chlorohydrin (10 μm) inhibited AR by 50% and reduced activation by less. When glucose was added to sperm incubated 2 hr with pyruvate and lactate, the number of AR observed after 4 hr was the same as that obtained when glucose was present throughout the incubation. When glucose was added after 3.5 hr, AR were delayed for 1 hr and lower numbers of sperm underwent AR. In the presence of lactate and pyruvate, 0.38 mM glucose was able to support activation and AR as well as 3.24 mM glucose. These results indicate that exogenous glucose and lactate are necessary for in vitro capacitation and AR of hamster sperm; only low levels of exogenous glucose are required; exogenous glucose is not required during the first 2 hr of capacitation; and glycolytic activity is necessary for capacitation and the AR.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120040605
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    Temperature dependence of capacitation in bat sperm monitored by zona-free hamster ova (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 525-533 
    Details
    ISSN: 0148-7280
    Keywords: capacitation ; fertilization ; spermatozoa ; in vitro ; Little Brown Bat ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The temperature dependence of capacitation in bat sperm (Myotis lucifugus lucifugus) was studied by monitoring fertilizations rates of zona-free hamster ova at different temperatures. Spermatozoa were cultured in BWW medium at temperatures 4°C, 24°C, 32°C, 42°C, and 55°C from 0-24 hr. Activation of sperm could be determined visually due to the change in movement seen through light microscopy. Activation was later confirmed by higher rates of fertilization. Preincubation of the bat sperm was found to have a direct effect on the success of penetration of the zona-free hamster ova. Holding bat spermatozoa at low temperature for long intervals allowed them to remain motile but unable to fertilize. Sperm are not irreversibly damaged, however, and activation, when the temperature is increased to 32°C, is faster than when sperm are intitially put at 32°C, resulting in good fertilization rates.
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    URL: http://dx.doi.org/10.1002/mrd.1120040606
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    Fine structural abnormalities in the developing mouse embryo (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 535-545 
    Details
    ISSN: 0148-7280
    Keywords: mouse ; embryo ; zygote ; electron microscopy ; reproductive physiology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Initial changes in the fine morphology of apparently normal mouse zygotes and embryos were studied in serial sections of mouse oviducts that had been fixed in situ. These changes included extra sperm in the perivitelline space, nuclear budding, the presence of large nucleoli, perinuclear vesicles, the concentration of cytoplasmic organelles, and the extrusion of cytoplasmic ground substance. Initial changes in the nucleus and cytoplasm were undetectable when the zygotes and embryos were examined with the light microscope. It was concluded that serious abnormalities in zygotes and embryos, which may not be identified at the light microscope level, may be detected if they are examined in the electron microscope. Therefore, zygotes and embryos should be critically evaluated before being rated as normal.
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    URL: http://dx.doi.org/10.1002/mrd.1120040607
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    The changes in sperm nuclei after penetrating fish oocytes matured without germinal vesicle material in their cytoplasm (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 121-132 
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    ISSN: 0148-7280
    Keywords: sperm nucleus ; fish oocyte ; germinal vesicle (GV) ; nuclear formation ; chromosome ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The processes occurring from sperm penetration to chromosome formation in the cytoplasm of Oocytes matured in vitro, after removal of the germinal vesicle (GV) and before hormonal stimulation, were observed with electron microscope. The dechorionated oocytes, matured without the participation of the GV material, responded to sperm penetration by initiating a cortical reaction within 20 seconds after insemination. The pentrating sperm nuclei transformed to male pronuclei with vesiculation of the nuclear membrane, chromatin decondensation, and formation of a pronuclear membrane. Before cleavage, however, no chromosome formation was observed in these oocytes. Instead, the fully grown pronuclei change to a picnotic chromatin mass without or with an only fragmented nuclear membrane, then disappeared. On the contrary, sperm nuclei that penetrated into the cytoplasm of naked eggs containing GV material during maturation underwent pronuclear and chromosomal formation. Judging from these observation in Oryzias oocytes, the GV material seems to be unnecessary for the formation of pronucleus from the compact sperm nucleus, but is essential for the process of chromosomal formation.
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    URL: http://dx.doi.org/10.1002/mrd.1120030204
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    Sertoli-germ cell interrelations: A review (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 179-202 
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    ISSN: 0148-7280
    Keywords: Sertoli cell ; spermatogenesis ; junction ; germ cell ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 17 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120030209
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980) 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120030301
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    Actin filaments and mitochondrial movement in vertebrate spermiogenesis (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 203-209 
    Details
    ISSN: 0148-7280
    Keywords: actin ; mitochondrial movement ; spermiogenesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The presence of actin filaments around mitochondria during vertebrate spermiogenesis was demonstrated by immunofluorescence and immuno-electron microscopy and by heavy meromyosin decoration. The presence of actin is supposed to be related to mitochondrial rearrangements occurring in the spermatid stage.
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    Bausteine von Oligosacchariden, XXXVI. Reaktivitätsuntersuchungen bei Tri- und Pentasaccharid-synthesen. Verbesserte Synthese der Pentasaccharidkette des Forssman-Antigens (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 2204-2215 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Building Units of Oligosaccharides, XXXVI.  -  Investigation of Reactivity in Tri- and Pentasaccharide Syntheses. Improved Synthesis of the Pentasaccharide Chain of the Forssman AntigenThe dependence of selectivity and yield upon the initial saccharide′s reactivity is shown for the syntheses of the trisaccharides 7, 8, 9, and 12. From 8 comes the trisaccharide halide 15 which, together with 22 in a block synthesis, yields the pentasaccharide 23 which in turn, after deprotection, gives the pentasaccharide chain of the Forssman hapten 25. This improved synthesis of 25 only uses 2-azido sugars and avoids the use of 2-phthalimido sugars.
    Notes: Die Abhängigkeit der Selektivität und der Ausbeute von den Reaktivitäten der Ausgangssaccharide bei der Synthese der Trisaccharide 7, 8, 9 und 12 wird gezeigt. Aus 8 ist der Trisaccharidhalogenid-Baustein 15 darstellbar, der in einer Blocksynthese mit 22 das Pentasaccharid 23 liefert, dessen Entblockierung zur Pentasaccharidkette des Forssman-Haptens 25 führt. Diese verbesserte Synthese von 25 verwendet nur 2-Azido-Zucker und vermeidet 2-Phthalimido-Zucker.
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    URL: http://dx.doi.org/10.1002/jlac.198119811209
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    Chemie an starren Grenzflächen, 6 Photochemisch induzierte Reaktionen mit grenzflächengebundenen SensibilisatorenHerrn Professor Dr. Tim Toepel zum 65. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 792-810 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry at Rigid Surfaces, 6.  -  Photochemically Induced Reactions with Surface-bound SensitizersAerosil® reacts with 3-triethoxysilylpropylamine to give Aminoaerosil(1) which can be converted into aerosils2a-f by means of sensitizers containing carboxyl groups. The density of the functional groups on the surface which was determined by several methods clearly effects the reaction. On irradiation in 2-propanol, acetone was produced as well as the surface-bound pinacol, e. g.4, which could be reoxidized by lead tetraacetate to give2b. Hydrodimerization on the surface of2b
    Notes: Aerosil® wird mit 3-Triethoxysilylpropylamin zu Aminoaerosil(1) umgesetzt und dieses mit carboxylgruppenhaltigen Sensibilisatoren in die grenzflächenmodifizierten Aerosile2a-f übergeführt. Die Beladungsdichte mit funktionellen Gruppen, die nach unterschiedlichen Methoden bestimmt wird, beeinflußt maβgebend das Reaktionsergebnis. Bei der Bestrahlung der grenzflächenmodifizierten Aerosile2a - c in Isopropylalkohol entstehen Aceton sowie das grenzflächengebundene Pinakol, z. B.4, das mit Bleitetraacetat wieder zu2b rückoxidiert werden kann. Die Hydrodimerisierung an der Grenzfläche von2b läuft 3mal langsamer als mit der Analogverbindung im Homogensystem. Bei der Photoreduktion von2b geringer Beladungsdichte entstehen neben dem Pinakol4 das grenzflächenfixierte Carbinol8 sowie das gemischte Pinakol9. An Aerosil grenzflächengebundene p-Acetylbenzoesäure (modifiziertes Aerosil2b) wird  -  in Analogie zu früher im Homogensystem durchgeführten Versuchen  -  in (S)-Milchsäure-(p-menth-3-ylester) und (R, S)-Milchsäure-(p-menth-3-ylester) bestrahlt. In beiden Fällen bildet sich grenzflächengebundenes Pinakol4, im zweiten Fall auch eine geringe Menge an optisch aktivem Lactat. Mit grenzflächengebundenen Sensibilisatoren werden folgende photochemisch induzierte Reaktionen studiert: a) die photosensibilisierte Addition von Isopropylalkohol an Maleinsäure und Maleinsäure-diethylester zu Terebinsäure(12a) bzw. deren Ethylester; b) die sensibilisierte cis/trans-Isomerisierung von Maleinsäure- bzw. Fumarsäure-diethylester; c) die sensibilisierte cis/trans-Isomerisierung von 1,2-Diphenylcyclopropan; d) die sensibilisierte Autoxidation von 2,5-Dimethylfuran. Bei allen vier Reaktionstypen entstehen  -  wenn auch langsamer  -  die gleichen Reaktionsprodukte wie mit analog strukturierten Sensibilisatoren im Homogensystem. Bei den Reaktionen b), c) und d) wurden der Wirkungsfaktor WF (Quotient der Reaktionsgeschwindigkeiten im Homogen- und Heterogensystem) sowie die Wiederverwendbarkeit SF (Quotient der Umsätze nach gleichen Zeiten im Zweit- und Erstversuch) der heterogen gebundenen Sensibilisatoren bestimmt.
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    Eine einfache Synthese von TetramethyloxamidKarl Dimroth zum 70. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1015-1017 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Simple Synthesis of TetramethyloxamideTetramethyloxamide has been prepared by a new and simple procedure from dimethylformamide, iron(II) sulfate heptahydrate, and tert-butyl hydroperoxide (yield 43%) or 30% aqueous hydroperoxide (yield 77%).
    Notes: Es wird eine neue, einfache Synthese von Tetramethyloxamid aus Dimethylformamid, Eisen(II)-sulfat-heptahydrat und tert-Butylhydroperoxid (Ausb. 43%) oder 30proz. Wasserstoffperoxid (Ausb. 77%) beschrieben.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198119810606
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    Synthese, thermische und photochemische Reaktionen neuer mesoionischer 1,3,2-Oxathiazolone (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1025-1034 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, Thermal and Photochemical Reactions of New Mesoionic 1,3,2-OxathiazolonesThe synthesis and spectroscopic data of the new mesoionic 1,3,2-oxathiazolones 3b, c, e are described. As cyclic thiocarbonyl imine, 3e reacts with dimethyl acetylenedicarboxylate at 80°C with evolution of carbon dioxide to produce the 5-arylisothiazole derivative 6e (80%). On the other hand, the visible light-induced fragmentation of 3e leads to a nitrile sulfide intermediate of type 10 which suffers unimolecular decay with formation of sulfur and the arylnitrile 11e or which can be partially trapped with dimethyl acetylenedicarboxylate to form the isomeric 3-arylisothiazole derivative 13e (29-21%). The analogous photochemical decay of 3c in the presence of dimethyl acetylenedicarboxylate proceeds with formation of the isothiazole derivative 13c besides sulfur and the nitrile 11c, whereas the nitrile sulfide 10b  -  photochemically generated from 3b  -  does not more react with formation of an isothiazole derivative.
    Notes: Die Synthese und spektroskopischen Daten der neuen mesoionischen 1,3,2-Oxathiazolone 3b, c, e werden beschrieben. Als cyclisches Thiocarbonylimin reagiert 3e mit Acetylendicarbonsäuredimethylester bei 80°C unter Kohlendioxid-Freisetzung zum 5-Arylisothiazol-Derivat 6e (Ausb. 80%). Demgegenüber führt die mit sichtbarem Licht induzierte Fragmentierung von 3e zu einer Nitrilsulfid-Zwischenstufe vom Typ 10, die unimolekularen Eigenzerfall in Schwefel und das Arylnitril 11e erleidet oder mit Acetylendicarbonsäure-dimethylester teilweise als isomerer 3-Aryl-isothiazol-Abkömmling 13e (Ausb. 29-21%) abgefangen werden kann. Der analoge photochemische Zerfall von 3c liefert in Gegenwart von Acetylendicarbonsäure-dimethylester neben Schwefel und dem Nitril 11c das Isothiazol-Derivat 13c, während das aus 3b photochemisch entstandene Nitrilsulfid 10b nicht mehr zur Isothiazol-Bildung befähigt ist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198119810608
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    Struktur und Reaktionen von 2,2′-Oxybis[2,2-dimethyl-4,4,5,5-tetrakis(trifluormethyl)-1,3,2λ5-dioxaphospholan]Professor Alfred Roedig zum 70. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1035-1043 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structure and Reactions of 2,2′-Oxybis[2,2-dimethyl-4,4,5,5-tetrakis(trifluoromethyl)-1,3,2λ5-dioxaphospholane]The structure of the title compound 3 has been determined by X-ray diffraction. 3 was found to crystallize in the monoclinic system (space group P21/c). Two crystallographically independent molecules are observed in the crystal lattice which differ with regard to the P - O - P angle [147.3(3)° and 150.8(3)°, respectively]. Formation of 3 has been observed in the reaction of the chlorophosphorane Me2P(pfp)Cl (2; pfp = perfluoropinacolyl) with NaHCO3, and of the siloxyphosphorane Me2P(pfp)OSiMe3 (1) with Me2P(= O)Cl. Cleavage of 3 with methanol furnishes the previously known compound Me2P(pfp)OMe (5) and the acyclic phosphinic acid ester Me2P(= O)OC(CF3)2C(CF3)2OH (4b). Reaction of 3 with water leads to exclusive formation of 4b; the isomeric hydroxyphosphorane Me2P(pfp)OH (4a) has not been observed.
    Notes: Die Struktur der monoklin (Raumgruppe P21/c) kristallisierenden Titelverbindung 3 wurde durch Röntgenstrukturanalyse bestimmt (Abb. 1-3). Im Kristallgitter werden zwei kristallographisch unabhängige Moleküle beobachtet, die sich in der Groβe des P - O - P-Winkels unterscheiden [147.3(3)° bzw. 150.8(3)°]. 3 bildet sich bei der Umsetzung des Chlorphosphorans Me2P(pfp)Cl (2; pfp = perfluorpinakolyl) mit NaHCO3 sowie aus dem Siloxyphosphoran Me2P(pfp)OSiMe3 (1) mit Me2P(= O)Cl. Die Spaltung von 3 mit Methanol liefert die bereits bekannte Verbindung Me2P(pfp)OMe (5) und den acyclischen Phosphinsäureester Me2P(= O)OC(CF3)2C(CF3)2OH (4b). Die Umsetzung von 3 mit H2O führt ausschließlich zu 4b; die Bildung des isomeren Hydroxyphosphorans Me2P(pfp)OH (4a) wird nicht beobachtet.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.198119810609
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    Elektron-Donor-Acceptor-Verbindungen, XXVII Chinhydrone der [4.4]Paracyclophan-ReiheHerrn Professor Dr. M. Seefelder zum 60. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1052-1064 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electron Donor-Acceptor Compounds, XXVII.  -  Quinhydrones of the [4.4]Paracyclophane SeriesIn the context of the determination of the distance and orientation dependence of charge-transfer interactions the diastereomeric quinhydrones 5 and 6 of the [4.4]paracyclophane series were prepared. Cyclisation of 1,4-bis(3-bromopropyl)-2,5-dimethoxybenzene with 2,5-dimethoxy-1,4-benzenedimethanethiol yielded the diastereomeric dithia[5.5]paracyclophanes 9/10 which, via the corresponding disulfones 11/12, were converted into the 6,9,16,19-tetramethoxy-[4.4]paracyclophanes 7/8. The stereoisomers 7/8, as well as the pairs of diastereomers 9/10 and 11/12. have been separated; experiments on thermal isomerisation are reported. The assignment of 7/8 to the pseudoortho and pseudogeminal constitution was established by an X-ray structure analysis of 7 the molecular structure of which is discussed. Oxidative demethylation of 7 and 8 yielded the diastereomeric quinhydrones 5 and 6. Charge-transfer absorptions of these compounds are compared with those of the corresponding [3.3]paracyclophane quinhydrones 3b and 4b and are discussed under the aspect of the specific conformational situation present in the [4.4]paracyclophane system.
    Notes: Zur Untersuchung der Abstands- und Orientierungsabhängigkeit der Charge-Transfer-Wechsel-wirkungen wurden die diastereomeren Chinhydrone 5 und 6 der [4.4]Paracyclophan-Rehe synthetisiert. Die Cyclisierung von 1,4-Bis(3-brompropyl)-2,5-dimethoxybenzol mit 2,5-Dimethoxy-1,4-benzoldimethanthiol ergab die diastereomeren Dithia[5.5]paracyclophane 9/10, die über die entsprechenden Disulfone 11/12 in die 6,9,16,19-Tetramethoxy[4.4]paracyclophane 7/8 über-führt wurden. Ebenso wie die Diastereomeren-Paare 9/10 und 11/12 lieβen sich auch 7/8 in die Stereoisomeren trennen; über Isomerisierungsversuche wird berichtet. Die Zuordnung von 7/8 zur pseudoortho- und pseudogeminalen Reihe geschah durch Röntgen-Strukturanalyse von 7, für das die Molekülstruktur diskutiert wird. Oxidative Demethylierung von 7 und 8 diastereomeren Chinhydrone 5 und 6. Die Charge-Transfer-Absorptionen dieser Verbindungen werden mit denen der entsprechenden [3.3]Paracyclophan-Chinhydrone 3b und 4b verglichen und unter dem Gesichtspunkt der im [4.4]Paracyclophan-System vorliegenden besonderen Konformationsverhältnisse diskutiert.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.198119810611
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    Elektron-Donor-Acceptor-Verbindungen, XXVIII Synthese und Charge-Transfer-Eigenschaften von 4,7-Diaza[2.2]paracyclophanen (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1065-1072 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electron Donor-Acceptor Compounds, XXVIII.  -  Synthesis and Charge-Transfer Properties of 4,7-Diaza[2.2]paracyclophanes
    Notes: 2,5-Bis(brommethyl)pyrazin (3) wurde dargestellt und mit 1,4-Benzoldimethanthiol und 2,5-Dimethoxy-1,4-benzoldimethanthiol zu den entsprechenden 5,8-Diaza-2,11-dithia[3.3]paracyclophanen cyclisiert. Photochemische Schwefel-Extrusion ergab 4,7-Diaza[2.2]paracyclophan (1) und die stereoisomeren 12,15-Dimethoxy-4,7-diaza[2.2]paracyclophane 5 und 6, die chromatographisch getrennt wurden.  -  Absorptions- und Emissionsspektren von 5 und 6 beweisen die π-Acceptor-Eigenschaft eines Pyrazins, das im [2.2]Paracyclophan-System einem starken Elektron-Donor gegenübersteht. Die beobachtete Lösungsmittelabhängigkeit der Charge-Transfer-Absorptionen von 5 und 6 (Abb.) wird auf eine Änderung der Elektronenaffinität des Pyrazin-Teils durch Solvatation und Protonierung zurückgeführt. Der Vergleich von Charge-Transfer-Eigenschaften der Stereoisomeren 5 und 6 zeigt die Orientierungsabhängigkeit der Donor-Acceptor-Wechselwirkung.2,5-Bis(bromomethyl)pyrazine (3) was prepared and cyclized with 1,4-benzenedimethanethiol and 2,5-dimethoxy-1,4-benzenedimethanethiol to give the corresponding 5,8-diaza-2,11-dithia[3.3]-paracyclophanes. Photochemical sulfur extrusion yielded 4,7-diaza[2.2]paracyclophane (1) and the stereoisomeric 12,15-dimethoxy-4,7-diaza[2.2]paracyclophanes 5 and 6 which were separated by chromatography.  -  Absorption and emission spectra of 5 and 6 demonstrate the π-acceptor quality of pyrazine when linked in a [2.2]paracyclophane system vis-a-vis to a strong electron donor. The solvent dependence of charge-transfer absorptions observed for 5 and 6 (Fig.) is ascribed to the change in electron affinity of the pyrazine moiety by solvation and protonation. By comparing charge-transfer properties of the stereoisomers 5 and 6 the orientation dependence of electron donor-acceptor interactions is shown.
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    URL: http://dx.doi.org/10.1002/jlac.198119810612
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    Reaktionen von 2-Aminomethylen-5-halogen-2H-pyrrolen und (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1207-1214 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of 2-Aminomethylene-5-halo-2H-pyrroles and 5-Halo-2-pyrrolecarbaldehydes, II.  -  Cyclotetramerizations of Suitable Pyrroles into Octamethylporphyrins without Acid CatalysisCyclotetramerizations of 2-aminomethyl- and 2-dimethylaminomethyl-3,4-dimethylpyrrole with dimethyl sulfate, methyl iodide, copper(II) acetate, zinc acetate, magnesium chloride, hydroperoxide, formaldehyde, benzaldehyde, and ethylmagnesium bromide have been investigated. The syntheses of the pyrroles 4-6, 8, and 9 are described.
    Notes: Die Cyclotetramerisierungen von 2-Aminomethyl- und 2-Dimethylaminomethyl-3,4-dimethylpyrrol mit Dimethylsulfat, Methyliodid, Kupfer(II)-acetat, Zinkacetat, Magnesiumchlorid, Wasserstoffperoxid, Formaldehyd, Benzaldehyd und Ethylmagnesiumbromid werden untersucht. Die Synthese der Pyrrole 4-6, 8 und 9 wird beschrieben.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198119810707
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    Synthesen einiger β-Mycaminoseglycoside (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1223-1233 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Some β-Mycaminose GlycosidesStarting from derivatives of 3-azido-3,6-dideoxy-α-α-glucofuranose 5 or 3-azidoglucofuranose 10 the 1-bromides 7, 14 and 30, suitable for glycoside synthesis under Koenigs-Knorr conditions, have been prepared. By reaction of 14 with methanol, cyclohexanol, benzyl alcohol, 2,2,2-trichloroethanol, and 1,2;3,4-di-O-isopropyliden-α-galactose the β-glycosides 16-20 are obtained in high yields. Reductive alkylation of 16, 17, and 20 with palladium on charcoal/formaldehyde gave the 3-dimethylamino compounds 21, 22, and 23. After their dehalogenation with tributyltin hydride, the corresponding β-glycosides 24, 25, and 26 of D-Mycaminose are received in high yields.
    Notes: Ausgehend von Derivaten der 3-Azido-3,6-didesoxy-α-D-glucofuranose 5 oder 3-Azidoglucofuranose 10 werden die für die Glycosidsynthesen unter Koenigs-Knorr-Bedingungen geeigneten 1-Bromhalogenosen 7, 14 und 30 dargestellt. Die Umsetzung von 14 mit Methanol, Cyclohexylalkohol, Benzylalkohol, 2,2,2-Trichlorethanol und 1,2;3,4-Di-O-isopropyliden-α-D-galactose führt in hohen Ausbeuten zu den β-Glycosiden 16-20. Die reduktive Alkylierung von 16, 17 und 20 mittels Palladiums auf Kohle/Formaldehyd-führt zu den 3-Dimethylaminoverbindungen 21, 22 und 23. Deren Enthalogenierung mit Tri-n-butylzinnhydrid verläuft in hohen Ausbeuten zu den entsprechenden β-Glycosiden 24, 25 und 26 der D-Mycaminose.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198119810709
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    Theoretische und spektroskopische Untersuchungen an Indigofarbstoffen, XXII Synthesen von 5,5′- und 6,6′-dialkylierten IndigofarbstoffenHerrn Prof. K. Dimroth zum 70. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1303-1333 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Theoretical and Spectroscopical Investigations of Indigo Dyes, XXII.  -  Preparations of 5,5′-and 6,6′-Dialkylated Indigo DyesThe manifolded applicabilities of indigo dyes are strongly restricted by the low solubility of most of their representatives. We describe in this paper the preparation of a series of dialkylated indigos 1, thioindigos 2, dyes of the cibaviolett-type 3, and of the corresponding vinylogues 4, 5, and 6 by different synthetic methods. Some of the prepared compounds show a remarkable solubility and can be used for spectroscopic measurements even in non-polar solvents.
    Notes: Die vielseitigen Verwendungsmöglichkeiten der Indigoide werden durch die geringe Löslichkeit der meisten Vertreter dieser Farbstoffklasse stark eingeschränkt. Wir berichten hier über die Darstellung einer Reihe dialkylierter Indigos 1, Thioindigos 2, Cibaviolett-Farbstoffe 3 sowie ihrer Vinylogen 4, 5 und 6 auf unterschiedlichen Wegen. Einige der Verbindungen zeigen eine sehr gute Löslichkeit und können in unpolaren Lösungsmitteln für spektroskopische Zwecke genutzt werden.
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    URL: http://dx.doi.org/10.1002/jlac.198119810717
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    Zuckertosylate via p-Toluolsulfinsäureester. p-Toluolsulfinimidazolid als Reagenz zur halogenidfreien Sulfinesterbildung (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1354-1360 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Sugar Tosylates via p-Toluenesulfinic Acid Esters.  -  p-Toluenesulfinimidazolide  -  A Reagent for Formation of Sulfinic Acid Esters without Using HalidesThe reaction of the protected sugar derivatives 1, 4, 7, 10, 13, 16, 19 and 20 with p-toluenesulfin-imidazolide prepared from p-toluenesulfinic acid and N,N'-carbonyldiimidazole yields the corresponding p-toluenesulfinic esters 2, 5, 8, 11, 14, 17, 20 and 22. With the exception of 20 and 22, these products can be oxidized with m-chloroperbenzoic acid in high yields and short overall reaction times to the tosylates 3, 6, 9, 12, 15 and 18.
    Notes: Durch Umsetzung der blockierten Zuckerderivate 1, 4, 7, 10, 13, 16, 19 und 21 mit dem aus p-Toluolsulfinsäure und N,N'-Carbonyldiimidazol intermediär gebildeten p-Toluolsulfinimidazolid werden die p-Toluolsulfinsäureester 2, 5, 8, 11, 14, 17, 20 und 22 erhalten. Daraus lassen sich mit Ausnahme von 20 und 22 in hohen Ausbeuten und insgesamt kurzer Reaktionszeit die entsprechenden Tosylate 3, 6, 9, 12, 15 und 18 durch Oxidation mit m-Chlorperbenzoesäure darstellen.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198119810803
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    Neue kondensierte Azole mit zwei Brückenkopf-Stickstoffen (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1361-1366 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Condensed Azoles with Two Bridgehead Nitrogen AtomsThe pyrazolo[1,2-a][1,2,4]triazoles 4, 1,2,4-triazolo[1,2-b]phthalazine 7, 1,2,4-triazolo[1,2-a]-[1,2,4]triazine 9, 1,2,4-triazolo[1,2-a]indazoles 16, 1,2,3,5-thiatriazolo[2,3-a]indazole 17 and 1,2,4-triazino[1,2-a]indazole 18 are prepared by the cycloreaction of the triazoles 1 or the triazole and indazole carboxamides 5, 6, 13, and 14 with 1,1-, 1,2-, 1,3-, and 1,4-dielectrophiles.
    Notes: Die Pyrazolo[1,2-a][1,2,4]triazole4, das 1,2,4-Triazolo[1,2-b]phthalazin 7, 1,2,4-Triazolo[1,2-a]-[1,2,4]triazin 9, die 1,2,4-Triazolo[1,2-a]indazole 16, das 1,2,3,5-Thiatriazolo[2,3-a]indazol 17 und 1,2,4-Triazino[1,2-a]indazol 18 werden durch Cycloreaktion der Triazole 1 bzw. der Triazol-und Indazolcarboxamide 5, 6, 13 und 14 mit 1,1-, 1,2-, 1,3- und 1,4-Dielektrophilen dargestellt.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198119810804
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    Stabile Carbeniumionen, 27. DiarylchlorcarbeniumionenHerrn Prof. Dr. G. Pfleiderer zum 60. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1415-1418 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stable Carbenium Ions, 271). - Diarylchlorocarbenium IonsDiarylchlorocarbenium hexachloroantimonates have been prepared as crystalline salts and are characterised.
    Notes: Diarylchlorcarbenium-hexachloroantimonate werden als kristalline Salze dargestellt und charakterisiert.
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    URL: http://dx.doi.org/10.1002/jlac.198119810810
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    Stabile Carbeniumionen, 28. α,α′-Dihalogen-α,α′-diphenyl-m-phenylendicarbeniumionenHerrn Prof. Dr. G. Fritz zum 60. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1419-1423 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stable Carbenium Ions, 281). - α,α′-Dihalogen-α,α′-diphenyl-m-phenylenedicarbenium Ionsα,α′-Difluoro-α,α′-diphenyl-m-phenylenedicarbenium hexafluoroantimonate and α,α′-dichloro-α,α′-diphenyl-m-phenylenedicarbenium hexachloroantimonate are prepared as crystalline salts and are characterised.
    Notes: α,α′-Difluor-α,α′-diphenyl-m-phenylendicarbenium-hexafluoroantimonat und α,α′-Dichlor-α,α′-diphenyl-m-phenylendicarbenium-hexachloroantimonat werden als kristalline Salze dargestellt und charakterisiert.
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    URL: http://dx.doi.org/10.1002/jlac.198119810811
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    Synthesen von Gallenfarbstoffen, XIII. Darstellung von 3,4-Dihydro-5(1H)-pyrromethenonen aus 5(1H)-Pyrromethenonen sowie 5(2H)-DipyrrylmethanonenHerrn Professor Dr. F. Bohlmann zum 60. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1492-1504 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Bile Pigments, XIII1).  -  Preparation of 3,4-Dihydro-5(1H)-pyrromethenones from 5(1H)-Pyrromethenones and from 5(2H)-Dipyrrylmethanones5(2H)-Dipyrrylmethanones 2 which are usually obtained by catalytical hydrogenation of 5(1H)-pyrromethenones 1, are only formed as the main product (ca. 80%) in alkaline solutions. In the absence of base, the obtained mixture contains up to 40% of the cis-configurated (Z)-3,4-dihydro-5(1H)-pyrromethenones (rac-3). On the other hand, the corresponding trans-isomers (rac-7) are available by base-catalyzed, irreversible rearrangement of 2 in boiling methanol in max. 40% yield. Under the same conditions (Z)-cis-3,4-dihydro-5(1H)-pyrromethenones (rac-3) are converted into the corresponding trans-isomers (rac-7), which can be isolated in 80% yield from the reaction mixture. In H3COD the products are deuterated at C-4 and at the methine bridge. (Z)-trans-3,4-Dihydro-5(1H)-pyrromethenones (rac-7) exchange only the H-atom at the methine bridge. Both cis- (rac-3) and trans-(Z)-3,4-dihydro-5(1H)-pyrromethenones (rac-7) can be transformed into the corresponding E-isomers rac-10 and rac-11, respectively, by photoisomerization at the exocyclic double bond.
    Notes: 5(2H)-Dipyrrylmethanone 2, die bekanntlich durch katalytische Hydrierung von 5(1H)-Pyrromethenonen 1 zugänglich sind, werden nur in alkalischem Medium als Hauptprodukte (ca. 80%) gebildet. In Abwesenheit von Base enthält das Produktgemisch bis zu 40% cis-konfigurierte (Z)-3,4-Dihydro-5(1H)-pyrromethenone (rac-3). Ihre trans-konfigurierten Z-Isomeren (rac-7) sind durch basenkatalysierte irreversible Umlagerung von 2 in siedendem Methanol in max. 40proz. Ausbeute zugänglich. Unter denselben Bedingungen isomerisieren cis-konfigurierte (Z)-3,4-Dihydro-5(1H)-pyrromethenone (rac-3) zu den entsprechenden (Z)-trans-Isomeren (rac-7), die in 80proz. Ausbeute isoliert werden können. In H3COD findet dabei H/D-Austausch an C-4 und an der Methin-Brücke statt. (Z)-trans-3,4-Dihydro-5(1H)-pyrromethenone (rac-7) tauschen dagegen nur das methinständige H-Atom aus. Sowohl cis- (rac-3) als auch trans-konfigurierte (Z)-3,4-Dihydro-5(1H)-pyrromethenone (rac-7) lassen sich in die entsprechenden E-Stereo-isomeren rac-10 bzw. rac-11 durch Photoisomerisierung der exocyclischen Doppelbindung über-führen.
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    Zur Cyclisierung von Salicylsäureamiden und Salicylohydroxamsäuren mit 1,1′-Carbonyldiimidazol (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1513-1514 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Cyclisation of Salicylamides and Salicylohydroxamic Acids with 1,1′-CarbonyldiimidazoleCyclisation of salicylamides 1a, b and salicylohydroxamic acids 1c, d with 1,1′-carbonyldiimid-azole (2) causes formation of 2H-1,3-benzoxazine-2,4(3H)-diones 4a-d. In contrast to statements in the literature isoimides 3 or isoxazoles 5 could not be isolated.
    Notes: Salicylsäureamide 1a, b und Salicylohydroxamsäuren 1c, d cyclisieren mit 1,1′-Carbonyldiimid-azol (2) zu 2H-1,3-Benzoxazin-2,4(3H)-dionen 4a-d. Isoimide 3 oder Isoxazole 5 konnten entgegen Literaturangaben nicht isoliert werden.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198119810824
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    Masthead (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981) 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198119810901
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    Dihydropyridine, VI. Diimidomalonsäurederivate in der Hantzsch-Pyridin-SyntheseHerrn Prof. Dr. Herbert Grünewald zum 60. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1523-1533 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dihydropyridines, VI1).  -  Derivatives of Diimido Malonic Acid in the Hantzsch Pyridine SynthesisOne-pot-condensation of aldehydes 6, 2,2′-methylenediimidazoline hydrochloride (7) and β-dicarbonyl compounds 10 leads to 1,2,3,7-tetrahydro-8-(2-imidazoline-2-yl)imidazo[1,2-a]pyridine hydrochloride 11. Michael addition of 7 to α,β-unsaturated ketones is followed by ring closure to give 16, 17, and 18. Condensation of the free base 8a with aldehydes 6 and 1,3-cyclohexanedione yields the fused imidazopyridines 19a-d. Compounds 20 and 21 are prepared by use of a second enamine in the one-pot-synthesis, thus furnishing another basic centre. 2,2′-Methylenedi(2-thiazoline) hydrochloride (22) is prepared by condensation of diethyl malonodiimidate and 2-amino
    Notes: Die Dreikomponenten-Kondensation von Aldehyden 6, 2,2′-Methylendiimidazolin-hydrochlorid (7) und β-Dicarbonylverbindungen 10 führt zu 1,2,3,7-Tetrahydro-8-(2-imidazolin-2-yl)imidazo-[1,2-a]pyridin-hydrochloriden 11. Die Verbindungen 16, 17 und 18 werden durch cyclisierende Michael-Addition von 7 an α,β-ungesättigte Ketone erhalten. Die freie Base 8a kondensiert mit 1,3-Cyclohexandion und den Aldehyden 6 zu den anellierten Imidazopyridinen 19a-d. Einsatz eines zweiten Enamins in der Dreikomponenten-Reaktion liefert die Verbindungen 20 und 21 mit einem weiteren basischen Zentrum. 2,2′-Methylendi(2-thiazolin)-hydrochlorid (22) wird durch Kondensation von Malondiimidsäure-diethylester und 2-Aminoethanthiol-hydrochlorid erhalten. Natronlauge liefert die freie Base 8b. Die 2,3-Dihydro-8-(2-thiazolin-2-yl) 7H-thiazolo[3,2-a]-pyridine 23, 25, 26, 28 und 29 sind durch cyclisierende Michael-Addition von 8b an verschiedene α,β-ungesättigte Carbonylverbindungen in Ethanol oder Eisessig zugänglich.
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    Malondiamidine, III. Synthese und Kondensationsreaktionen des 1,2,3,4,6,7-Hexa-hydro-7-imino-1,4-dimethyl-5H-1,4-diazepin-5-ons (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1545-1549 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Malonodiamidines, III.  -  Synthesis and Condensation Reactions of 1,2,3,4,6,7-Hexahydro-7 imino-1,4-dimethyl-5H -1,4-diazepin-5-oneDiethyl malonodiimidate dihydrochloride (I) and N-methylethylenediamine yield in ethanol the N,N'-bridged malonodiamidine salt 2b, whereas 1 and N,N'-dimethylethylenediamine fail to give the 2b analogous salt 4. Instead the 1 H-1,4-diazepine-5,7-diimine hydrochloride 5 is obtained in low yield. Under hydrolytic reaction conditions the hydrochloride of the title compound is obtained in 56% yield. [3 + 3]-Condensations of the corresponding base 7 with 2,4-pentanedione and α,β-unsaturated carbonyl compounds lead to the diazepines 8, 9, and 10. 1 H-[1,4]diazepino-[5,6-b]quinolines 12a- f are obtained by condensation of 6 with the isatines 11.
    Notes: Malondiimidsäure-diethylester-dihydrochlorid (1) liefert mit N-Methylethylendiamin in Ethanol das N,N'-verbrückte Malondiamidiniumsalz 2b. Umsetzung von 1 mit N,N'-Dimethylethylendiamin führt wider Erwarten nicht zum 2b analogen Salz 4, sondern in geringer Ausbeute zum 1 H-1,4-Diazepin-5,7-diiminsalz 5. Unter hydrolytischen Reaktionsbedingungen wird das Hydrochlorid der Titelverbindung mit 56% Ausbeute erhalten. Die zugrundeliegende Base 7 geht mit 2,4-Pentandion und α,β-ungesättigten Carbonylverbindungen [3 + 3]-Kondensationen zu den Diazepinen 8, 9 und 10 ein. Die Isatine 11 kondensieren mit 7 zu den 1 H-[1,4]Diazepino[5,6-b]-chinolinen 12a- f.
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    URL: http://dx.doi.org/10.1002/jlac.198119810904
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    Kondensationen mit Oxim-O-sulfonaten, I. Synthese von 2-Amino-4,5-dihydro-4,5-diimino-1 H-pyrrol-3-carbonsäureesternHerrn Prof. Dr. Herbert Grünewald zum 60. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1561-1567 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Condensations with Oxime O-Sulfonates, I.  -  Synthesis of 2-Amino-4,5-dihydro-4,5-diimino-1 H-pyrrole-3-carboxylatesThe reaction of the oxime O-tosylates 1 with the amidinoacetic acid esters 2 does not lead to the expected pyrazines 4, but rather to the novel 4,5-dihydro-1 H-pyrrole-3-carboxylates 8 (= 2-pyrroline-3-carboxylates) by rearrangement via 7. The hydrolysis of the pyrroles 8 and their reactions with amines have been studied.
    Notes: Die Reaktion der Oxim-O-tosylate 1 mit den Amidinoessigestern 2 führt nicht zu den erwarteten Pyrazinen 4, sondern unter Umlagerung über 7 zu den neuartigen 4,5-Dihydro-1 H-pyrrol-3-carbonsäureestern 8 (= 2-Pyrrolin-3-carbonsäureester). Die Hydrolyse der Pyrrole 8 sowie deren Umsetzung mit Aminen wird untersucht.
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    URL: http://dx.doi.org/10.1002/jlac.198119810906
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    Verzweigte Zucker, XXVII. Kettenverlängerungen zu langkettigen Sacchariden durch Reaktionen mit dem Dianion des 1,3-Dithian-2-methanols und verwandten Dianionen (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 2009-2027 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Branched Sugars, XXVII1).  -  Synthesis of Long Chain Saccharides by Chain Elongation with the Dianion of 1,3-Dithiane-2-methanol and Related DianionsThe dianions 3, 4, and 16, which are suitable for nucleophilic addition to aldehydo-saccharides, can be obtained by reaction of 1,3-dithiane-2-methanol, or the appropriate side chain-elongated derivatives, with 2 molar equivalents of butyllithium. With these dianions, chain elongated saccharides can be made and, in one step, various potential chiral centres may be introduced. The octose 18, the decose 21, and the undecose 22 are obtainable from 17. With 23, the elongation of the chain leads to the septose 25, the nonose 27, and the decose 28. A 2-septulose 35 and 5-deculose 37 were also made.
    Notes: Durch Umsetzung von 1,3-Dithian-2-methanol und entsprechenden an der Seitenkette verlängerten Derivaten mit 2 Moläquivalenten Butyllithium lassen sich Dianionen 3, 4 und 16 darstellen, die zur nucleophilen Addition an aldehydo-Saccharide geeignet sind. Dabei werden kettenverlängerte Saccharide erhalten, bei denen in einem Schritt mehrere vorgegebene chirale Zentren eingeführt werden können. Aus 17 sind so die Octose 18, die Decose 21 und die Undecose 22 zu erhalten. Mit 23 führt die Kettenverlängerung zur Septose 25, zur Nonose 27 und Decose 28. Auch eine 2-Septulose 35 und 5-Deculose 37 sind darstellbar.
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    Zur Konfiguration des Nardosinons (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 2057-2060 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Configuration of NardosinoneX-ray analysis of nardosinone (1) shows cis position of the 1,2-dioxolane ring. Therefore, the formation of nardofuran (3) from isonardosinone (2) takes place by retention of the configuration at C-4.
    Notes: Die Röntgenstrukturanalyse zeigt, daß im Nardosinon (1) der 1,2-Dioxolan-Ring in cis-Stellung steht. Die Bildung des Nardofurans (3) aus Isonardosinon (2) verläuft daher unter Retention der Konfiguration an C-4.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.198119811113
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    Versuche zur Reduktion des DichlormethandisulfonyldichloridsHerrn Prof. Dr. L. Horner zum 70. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 2090-2092 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Experiments Concerning the Reduction of Dichloromethanedisulfonyl DichlorideMild reducing agents, including methanol, reduce dichloromethanedisulfonyl dichloride (2) to give dichloro(chlorosulfonyl)methanesulfinic acid (6) which desulfinylates spontaneously to form dichloromethanesulfonyl chloride (9). Chloromethanedisulfonyl dichloride (12) ist not reduced under these conditions and can be derivatized „normally“, for instance with morpholine.
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    URL: http://dx.doi.org/10.1002/jlac.198119811119
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    Berichtigung (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 2097-2097 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198119811122
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    Untersuchungen an natürlichen γ- und δ-Lactonen, XI. Synthese von Psilotin und 6-Epipsilotin (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 2384-2391 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Natural γ- and δ-Lactones, XI.  -  Synthesis of Psilotin and 6-EpipsilotinThe glucoside psilotin (1) and its 6-epi isomer were synthesized. From CD measurements the 6S-configuration can be assigned to 1.
    Notes: Psilotin (1) und 6-Epipsilotin wurden synthetisiert. CD-Messungen an diesen Verbindungen legen für natürliches Psilotin die 6S-Konfiguration fest.
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    URL: http://dx.doi.org/10.1002/jlac.198119811222
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    Asymmetrische Synthesen über heterocyclische Zwischenstufen, X. Enantioselektive Synthese von (2R)-2-Methylserinen (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 2407-2418 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Syntheses via Heterocyclic Intermediates, X.  -  Enantioselective Synthesis of (2R)-2-MethylserinesAldehydes and ketones react with the lithiated bislactim ether 3 of cyclo-(L-Ala-L-Ala) with 81 to 〉 95% asymmetric induction (d. e. = diastereomeric excess) at C-3; (R) configuration is formed predominantly.  -  A model concept for the asymmetric induction is proposed.  -  With aldehydes or unsymmetrical ketones C-7 of the adducts 6 becomes a chiral center, too. (R) configuration is induced here [for the (3R)-isomers] with d. e. 47-73%. Hydrolysis of the addition products 6 (0.25 N HCl, room temperature) gives L-Ala-OCH3 and (2R)-2-methylserine methyl esters 7. Both compounds can be separated either at the ester stage by distillation or  -  if 7 is thermolabile  -  after further hydrolysis at the amino acid stage.
    Notes: Die Umsetzung des lithiierten Bislactimethers 3 von cyclo-(L-Ala-L-Ala) mit Aldehyden und Ketonen vollzieht sich mit 81 bis 〉 95% asymmetrischer Induktion (d. e. = diastereomeric excess) an C-3, wobei die (R)-Konfiguration induziert wird.  -  Eine Modellvorstellung zur Deutung dieser ungewöhnlich hohen Induktion wird diskutiert.  -  Bei Aldehyden oder unsymmetrischen Ketonen wird auch C-7 der Addukte 6 zu einem Chiralitätszentrum; hier wird [bei den (3R)-Isomeren] mit 47-73% d. e. ebenfalls (R)-Konfiguration induziert.  -  Hydrolyse der Addukte 6 (0.25 N HCl, Raumtemperatur) liefert neben L-Ala-OCH3 die (2R)-2-Methylserin-methylester 7. Die bei-den Verbindungen lassen sich entweder auf der Stufe der Ester destillativ trennen oder  -  wenn 7 thermolabil ist  -  nach weiterer Hydrolyse auf der Stufe der Aminosäuren.
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    URL: http://dx.doi.org/10.1002/jlac.198119811224
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    Role of cumulus cells for rat oocyte maturation and metabolism (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 133-140 
    Details
    ISSN: 0148-7280
    Keywords: rat oocytes ; maturation ; oxygen consumption ; cumulus cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Oocytes collected from immature PMSG-treated rats on the morning of proestrus were allowed to mature in culture either surrounded by their cumulus cells or after denudation. It was found that the time course of oocyte nuclear maturation was similar whether the cumulus cells were present or not. The oxygen consumption of noncultured oocytes was 0.12 nl/hr/oocyte and increased by 40% after four to eight hours in culture with intact cumulus. Respiration of oocytes cultured without cumulus remained constant throughout the culture, except for a transient decrease after four hours.It is concluted that the cumulus cells do not affect the spontaneous nuclear maturation in vitro, but that the metabolism in oocytes cultured with intact cumulus is different from that of cultured denuded oocytes. Furthermore, it appears that the rise in oocyte oxygen consumption is not a prerequisite for nucler maturation.
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    URL: http://dx.doi.org/10.1002/mrd.1120030205
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    Immunocytochemical studies on the zona pellucida of cow blastocysts (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 141-148 
    Details
    ISSN: 0148-7280
    Keywords: cow blastocysts ; zona pellucida ; stability and location of antigenic material ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Labeling of the zona pellucida of cow blastocysts with zona-specific anti-serum shows that antigenicity is unaffected by abnormal cleavage, in vitro culture, or frozen storage. The uniform labeling in thin sections indicates that the zona pellucida is homogeneous antigenically. Heavier labeling of the inner and outer surfaces of the zona pellucida in thick sections appers to be due to greater porosity of these regions, in which the zona material becomes highly dispersed, or even partly solubilized, thereby permitting the formation of an antigen-antibody matrix.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120030206
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    Identification and hormonal control of reproductive-tract-specific antigens present in rabbit oviductal fluid (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 169-177 
    Details
    ISSN: 0148-7280
    Keywords: oviduct ; oviductal fluid ; mucin ; steroids ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Utilizing the intra-abdominal flask technique to collect oviductal fluid, the presence of two or possibly three reproductive-tract-specific antigens have been observed in rabbit oviductal fluid. Two of these antigens may be accounted for by the two forms of uteroglobin. The other antigen has a molecular weight greater than 200,000 daltons and its concentration in oviductal fluid is under hormonal control. During pseudopregnancy (PSP), when progesterone concentrations are high, or upon progesterone administration, the concentration of this high molecular weight antigen doubles in oviductal fluid. This correlates well with the previously observed increase in release of secretory products from the oviductal epithelia.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120030208
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    Ultrastructural studies of spermatogenesis in the anthocerotales. III. Gamete morphogenesis: From spermatogenous cell through midstage spermatid (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 149-167 
    Details
    ISSN: 0148-7280
    Keywords: Bryophyta ; Phaeoceros ; spermatid morphogenesis ; spermatogenesis ; ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: An ultrastructural examination of spermatogenesis in Phaeoceros has shown nucleoli to be present in spermatogenous cells and to persist until the centrioles become associated with nuclei of young spermatids. At the onset of multilayered structure (MLS) formation, well-defined aggregations of osmiophilic strands begin to form in the nuclei of young spermatids and disappear shortly after chromatin condensation starts in the midstage spermatids. When the centrioles in the young spermatids are orientated perpendicular to the nuclear envelope, the nucleoplasm immediately in front of them is densely stained. Where the spline tubules of the MLS extend over the nucleus, the nuclear envelope is devoid of pores, and the inner nuclear membrane is contacted internally by the local deposition of dense staining nucleoplasm. Chromatin condensation begins with strands extending perpendicularly from the dense staining nucleoplasm beneath the spline and continues with the nuclear beak becoming filled with condensed chromatin. As the MLS lamellae disappear acropetally, the rear portion of the anterior mitochondrion (AM) extends back under the nuclear beak which now narrows to a size that approximates the anterior end of the nucleus of a spermatozoid. By the end of the mid-spermatid stage, the nucleus has coiled approximately one gyre of a helix and the five or six central slpine tubules extend over the plastid which is now located beneath the front end of the AM. Several profiles of endoplasmic reticulum confluent with the nuclear envelope are present. Possible factors which might play a role in determining the morphology of the mid-spermatids are discussed.
    Additional Material: 21 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120030207
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    A new procedure for rapidly scoring acrosome reactions of human sperm (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 211-216 
    Details
    ISSN: 0148-7280
    Keywords: acrosome ; human sperm ; lectin ; capacitation ; fertilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Because the acrosome of human sperm is too small to be directly visualized by phase-contrast microscopy, acrosome reactions (that is loss of the acrosome) are generally not evaluated in studies of human sperm capacitation and fertilization. Nevertheless, it would be useful in such studies to have a technique for easily identifying and quantitating acrosome-reacted sperm. In this paper, we describe a method for labeling the human sperm acrosome with fluorescein-conjugated Ricinus communis agglutinin-60 (FITC-RCA); we show that in sperm without acrosomal caps, FITC-RCA labeling occurs either not at all or only in the equatorial segment of the acrosome. To determine if the absence of FITC-RCA labeling in the acrosomal cap region gives a reliable estimate of acrosome reactions, washed sperm or sperm incubated in a capacitating medium (BWW) were divided into two groups, which were then fixed for FITC-RCA labeling or transmission electron microscopy. Counts of acrosome reactions made by each method were similar, and we observed an increase in the percentage of reactions following incubation in BWW. We conclude that the FITC-TCA labeling technique is a reliable method for accurately scoring the percentage of acrosome-reacted human sperm.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120030303
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981) 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040101
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  • 90
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    Foreword (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 1-1 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040102
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  • 91
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    Preimplantation embryonic development of spontaneous mouse parthenotes after oocyte meiotic maturation in vitro (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 3-13 
    Details
    ISSN: 0148-7280
    Keywords: oocyte maturation ; parthenogenesis ; preimplantation development ; gonadotropins ; mouse ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Of eggs ovulated in LT/Sv mice, 10-20% undergo spontaneous parthenogenetic activation, and 40-50% of the parthenotes develop to blastocysts when cultured in simple defined medium from the one-cell stage. Similar percentages of oocytes isolated from Graafian follicles undergo parthenogenetic activation after spontaneous maturation in simple defined medium, but embryonic development proceeds no further than the two-cell stage. The simple defined medium that supported preimplantation development of ovulated eggs and spontaneous maturation of extrafollicular oocytes contained no serum, free amino acids, or vitamins. The present experiments were conducted to determine what conditions during spontaneous maturation of extrafollicular oocytes could promote the ability of oocytes to develop to blastocysts after parthenogenetic activation and mimic the environment of preovulatory follicles.Cumulus-enclosed oocytes that were matured in simple medium supplemented with fetal bovine serum (FBS) developed to blastocysts after spontaneous parthenogenetic activation. Furthermore, minimum essential medium (MEM), a complex medium containing free amino acids and vitamins, could substitute completely for FBS for maturing oocytes from (C57BL/6J × LT/Sv)F1 mice, and to a lesser extent for maturing LT/Sv oocytes. Therefore, even though germinal vesicle breakdown in mouse oocytes and preimplantation development of mouse eggs can occur in the absence of an exogenous supply of free amino acids and vitamins, a complete, or normal, mouse oocyte maturation cannot. These results also demonstrated that gonadotropins are not necessary during oocyte meiotic maturation for parthenogenetically activated eggs to develop through the preimplantation stages.Luteinizing hormone or 17β-estradiol in MEM during oocyte maturation had no effect on the subsequent development of parthenotes. In contrast, follicle stimulating hormone (FSH) and progesterone in the maturation medium decreased the number of ova that subsequently cleaved, and FSH decreased the number of cleaved eggs that developed to blastocysts.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120040103
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  • 92
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    Optimization of culture conditions for the formation of sperm cells in pollen tubes of tradescantia (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 35-40 
    Details
    ISSN: 0148-7280
    Keywords: sperm ; pollen tube ; culture media ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A culture medium and culture conditions are described that enable generative cell division and sperm formation to occur in a large proportion (greater than 70%) of the pollen tubes of Tradescantia paludosa within six to eight hours of culture of pollen. The nature of the nitrogen source, speed of shaking, and ratio of pollen to medium are important parameters in determining the extent of sperm formation. Addition of the plant hormones indole acetic acid, gibberellic acid, and kinetin to the growth medium does not influence generative cell division.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120040106
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  • 93
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    Mechanism of sperm-binding inhibition by anti-zona antisera (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 41-47 
    Details
    ISSN: 0148-7280
    Keywords: zona pellucida ; antibody ; sperm receptors ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mouse zonae pellucidae contain receptors for sperm throughout their structure since spermatozoa will bind to both the inner and outer surfaces of isolated zona fragments. Antibodies raised against mechanically isolated mouse zonae pellucidae were only capable of suppressing sperm binding to the outer zona surface in association with the formation of a precipitate in this region.These results indicate that such antisera are not capable of interacting directly with the sperm receptors on the zona pellucida but rely upon the less efficient mechanism of steric hindrance to prevent sperm from gaining access to the sperm binding sites.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120040107
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  • 94
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    The effects of taurine and hypotaurine on in vitro fertilization in the golden hamster (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 57-63 
    Details
    ISSN: 0148-7280
    Keywords: taurine ; hypotaurine ; spermatozoa ; in vitro fertilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Taurine and hypotaurine were examined for their efficacy in replacing sperm motility factor (SMF), prepared from bovine adrenal cortex, for in vitro fertilization in the golden hamster. Combinations of these amino acids at concentrations of 0.001, 0.01, 0.1, and 1 mM together with 16 μM isoproterenol (a catecholamine β-agonist) were added to the sperm incubations. After three hours of sperm preincubation, oviductal eggs were added to the sperm suspensions and examined for penetration and stage of fertilization after three or five hours of culture. At 0.001 mM, neither taurine or hypotaurine was capable of maintaining motility of hamster sperm for four to 4½ hours or of inducing fertilization. With all other concentrations, both amino acids were found to maintain motility of sperm as well as SMF. Hypotaurine stimulated motility to a greater extent than taurine and both required isoproterenol for the greatest motility. A low proportion of cumulus-free ova were fertilized when sperm were preincubated with either amino acid alone over the range of 0.01 to 1 mM; however, over 80% fertilization was consistently obtained when isoproterenol was also present during sperm incubation. Proportions of ova fertilized with taurine or hypotaurine present during sperm preincubation were comparable to those achieved with SMF. The possibility that taurine or hypotaurine is the sperm motility factor is discussed.After three hours of sperm/egg incubation, a lag in the early events of fertilization was observed in experimental groups treated with one of the amino acids (0.01 mM) alone compared with groups treated with isoproterenol present. However, if sperm/egg incubation was extended from three to five hours, no increase in number of eggs penetrated was found. Therefore, the delay observed at three hours was considered a function of fewer numbers of capacitated sperm present in the absence of isoproterenol rather than of the need for an extended capacitation time.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120040109
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  • 95
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    An automated procedure to measure DNA synthesis in preimplantation mouse embryos (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 121-131 
    Details
    ISSN: 0148-7280
    Keywords: preimplantation mouse embryos ; DNA synthesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: This paper describes a sensitive, reproducible, and automated procedure to measure DNA synthesis in preimplantation mouse embryos. Conditions for the DNA synthesis assay have been optimized as follows: (1) 4 μCi/ml3H-thymidine (sp. act. 20 Ci/immole); (2) a labeling period from 2 to 7 hours; (3) a 3-hour preincubation period for blastocysts and from 0 to 7 hours preincubation for 8-cell embryos; and (4) from 1 to 64 embryos per assay. The amount of DNA synthesis per embryo was found to be directly proportional to the number of cells (nuclei) per embryo. The described assay should be useful for future studies on the effect of synthetic and natural compounds on the development of preimplantation mouse embryos, as measured by perturbations in embryonic DNA synthetic activity.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120040206
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  • 96
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    Evidence that selenium in rat sperm is associated with a cysteine-rich structural protein of the mitochondrial capsules (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 139-149 
    Details
    ISSN: 0148-7280
    Keywords: selenium ; rat sperm ; mitochondrial capsules ; cysteine ; protein ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The keratinous capsules surrounding rat sperm mitochondria were isolated 24 days after intratesticular injections of [75Se] selenite or [35S] cysteine. Dodecyl sulfate-polyacrylamide gel electrophoresis of purified, doubly labeled mitochondrial capsules revealed only a single 75Se-labeled component, whose molecular weight was 17,000, in agreement with previously reported observations obtained with cruder sperm fractions. Most of the 35S label and the major zone of stained protein on the gels coincided with the position of 75Se, suggesting that selenium is associated with a cysteine-rich structural protein. The level of selenium in rat sperm, 195 ± 3.2 ng/108 sperm (approximately 30 ppm), determined by hydride generation and atomic absorption spectrophotometry, is consistent with a structural function for this trace element in the sperm.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120040208
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  • 97
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    Effects on spermiogenesis in the mouse of a male sterile neurological mutation, Purkinje cell degeneration (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 185-192 
    Details
    ISSN: 0148-7280
    Keywords: spermiogenesis ; sperm abnormalities ; sterility ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Purkinje cell degeneration (pcd) is a neurological mutation in the mouse that causes male sterility, but not female sterility. In order to assess the effects of this mutation on spermiogenesis, the structure of the testis and of epididymal spermatozoa was examined by transmission and scanning electron microscopy. In the mutant males, the sperm count was reduced, sperm were nonmotile, and 93% of the sperm were characterized by structural abnormalities of the head, the tail, or both. In the testes of mutant mice, Sertoli cell structure was normal, as were also the early stages of spermiogenesis. However, the elongating and maturing spermatids were characterized by abnormally shaped heads and tails with extraneous and ectopic outer dense fibers. These defects were common in the testes of the mutant mice and rare in the testes of the littermate control mice. It was concluded that the structural abnormalities of the pcd sperm occurred during spermiogenesis and were not due to degeneration of the sperm in the epididymis. These structural abnormalities are similar to those found in all other reported male sterile mutants of the mouse; therefore, although they are caused by the expression of the pcd gene, they are not unique to the expression of this gene.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120040303
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  • 98
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    Fertilization in the sea urchin arbacia punctulata inhibited by fluorescein dyes: Evidence for a plasma membrane mechanism (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 219-229 
    Details
    ISSN: 0148-7280
    Keywords: fertilization ; sea urchin ; Arbacia punctulata ; Erythrosin B ; dyes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Fertilization and ionophore activation of the sea urchin Arbacia punctulata were inhibited in the presence of six analogs of the dye fluorescein. The concentration of any one dye needed for blockage of sperm or Ca-ionophoremediated activation in 50% of the eggs (I50) was a function of the dye's lipid solubility. Substantially higher concentrations of each dye were required to block activation by Ca-ionophore (A23187) than were needed to inhibit sperm activation. A detailed study of the action of Erythrosin B (tetraiodofluorescein) showed that its effects were readily reversible. The I50 concentration of Erythrosin B increased as temperature increased from 10 to 25°C. The kinetics of blockage indicated that Erythrosin B blocked some early step in the program of fertilization. The results suggest that these anionic dyes may inhibit fertilization by preventing successful sperm-egg fusion.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040306
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  • 99
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    The generation and propagation of double waves in mosquito (Aedes notoscriptus) sperm-tails (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 241-250 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoan movement ; insect; axoneme ; accessory tubule ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In the mosquito Aedes notoscriptus nine accessory tubules develop from the doublets of the axoneme whose single central fibre forms late in spermiogenesis. The 9 + 9 + 1 mosquito sperm-tail propagates two waves of differing frequency and amplitude. The structural basis for the movement is of interest.Mosquito sperm were demembranated until all movement ceased and were reactivated with a solution containing adenosine triphosphate (ATP). They immediately moved in a normal fashion. Like untreated sperm, they always propagated double waves. This indicates that the plasma membrane does not control the double wave.After sonicating sperm treated as above, the high-frequency, low-amplitude waves sometimes propagated alone beyond a damaged region of sperm-tail, whereas the large-amplitude, low-frequency waves never propagated alone beyond a damaged region. This suggests that the latter waves are generated by an anterior site, possibly the centriole or centriole adjunct. The structure that propagates the large amplitude wave is not known; possibly the accessory tubules may slide against the axonemal doublets.Any region of the sperm-tail is capable of generating and propagating the low-amplitude, high-frequency wave, for which the structure responsible is probably the axoneme.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1120040308
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  • 100
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981) 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040401
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