ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (246)
  • Polymer and Materials Science  (240)
  • cell motility  (6)
  • Wiley-Blackwell  (246)
  • Elsevier
  • Institute of Physics
  • National Academy of Sciences
  • Periodicals Archive Online (PAO)
  • Springer Nature
  • 1985-1989  (246)
  • 1980-1984
  • 1975-1979
  • 1970-1974
  • 1987  (128)
  • 1985  (118)
  • Medicine  (246)
  • Sociology
  • Energy, Environment Protection, Nuclear Power Engineering
Collection
  • Articles  (246)
Publisher
  • Wiley-Blackwell  (246)
  • Elsevier
  • Institute of Physics
  • National Academy of Sciences
  • Periodicals Archive Online (PAO)
  • +
Years
  • 1985-1989  (246)
  • 1980-1984
  • 1975-1979
  • 1970-1974
Year
  • 1
    ISSN: 0886-1544
    Keywords: cell motility ; sensory transduction ; slime mold ; pseudopod formation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In an aggregation territory of Dictyostelium discoideum, outwardly moving, nondissipating waves of the chemoattractant cAMP sweep across each ameba. At the front of each wave, an ameba experiences an increasing temporal and a positive spatial gradient of cAMP. At the back of a wave, an ameba experiences a decreasing temporal and a negative spatial gradient of cAMP. Employing a perfusion chamber, we have mimicked the temporal dynamics of these waves in the absence of a spatial gradient and demonstrated that the frequency of lateral pseudopod formation and the frequency of turning are dramatically affected by the direction and dynamics of the temporal gradient. In addition, since an ameba will move in a directed fashion up a shallow, nonpulsatile gradient of cAMP, we also mimicked the increasing temporal gradient generated by an ameba moving up a shallow spatial gradient. The frequency of lateral pseudopod formation and the frequency of turning were depressed. Together, these results demonstrate that amebae can assess the direction of a temporal gradient of chemoattractant in the absence of a spatial gradient and alter both the frequency of pseudopod extension and turning, accordingly. Although these results do not rule out the involvement of a spatial mechanism in assessing a spatial gradient, they strongly suggest that the temporal dynamics of a cAMP wave or the temporal gradient generated by an ameba moving through a spatial gradient may play a major role in chemotaxis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 7 (1987), S. 368-380 
    ISSN: 0886-1544
    Keywords: cell motility ; rapid freezing ; cytoskeletal architecture ; immunocytochemistry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In this study I describe the ultrastructural distribution of myosin in cortical and subcortical areas of antibody-labelled, quick-frozen fibroblasts. In many cells myosin was present in small variably spaced and sized (0.23-0.39 μm long), nonaligned patches, while in other cells much larger periodically spaced patches of more uniform length (0.27 μm) were found. In all regions of the cytoskeleton myosin was found, primarily on linear bundles of actin filaments running parallel to the cell's long axis.Myosin was absent from single actin filaments, actin Filaments perpendicular to actin bundles aligned with the cell's long axis, and actin filaments, such as geodome vertices and parts of the cortex, which had a complex interwoven appearance. These data indicate that in motile non-muscle cells myosin exerts force only in a unidirectional manner. Recognisable myosin filaments were never observed even in cells incubated either in N-ethylmaleimide or sodium azide. The presence of myosin in, and almost to the very edge of, the cortex suggests that the cellular control of actomyosin based movement is direct and over short-range distances. Large numbers of small cross-linking filaments were found in association with cortical and subcortical actin. Their relationship to myosin and overall actin geometry is discussed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 17-29 
    ISSN: 0886-1544
    Keywords: cell motility ; membrane recycling ; immunofluorescence microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mouse peritoneal macrophages subjected to gradients of activated mouse serum were found by immunofluorescence observations to have their Golgi apparatus and their microtubule-organizing center largely oriented in the direction of the gradient. By analogy with similar results obtained with motile fibroblasts, it is proposed that these two organelles are rapidly and coordinately reoriented inside the macrophages in order to direct the insertion of new membrane mass, via vesicles derived from the Golgi apparatus, into the leading edge of the cell. Consistent with the importance of such membrane insertion to cell migration, we found that the ionophore monensin, an inhibitor of Golgi functions, inhibited cell motility in the chemostactic gradient. It was further shown that several inhibitors of chemotaxis (monensin, cytochalasin D, cycloheximide) did not inhibit the reorientation of the Golgi apparatus/microtubule-organizing center in cells exposed to a chemotactic gradient, and that the reorientation required extracellular Ca+2.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 103-122 
    ISSN: 0886-1544
    Keywords: gliding ; cell motility ; cytoskeleton ; diatoms ; capping ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Gliding motility was investigated in the marine diatom, Amphora coffeaeformis. Ultrastructural, biochemical, and pharmacological protocols were employed to probe the possible involvement of cytoskeletal proteins and a secretory process in gliding motility. Motility rate was measured using a video recording apparatus, and the effects of various cytoskeleton-disrupting drugs on motility were tested. Cytochalasins D and E, podophyllotoxin, and vinblastine (all at 25 μUg/ml) reversibly inhibited motility, as did monensin (10 μUM) and pronase (25 μUg/ml). Biochemical protein analysis of whole-cell extracts by one- and two-dimensional polyacrylamide gel electrophoresis revealed polypeptides comigrating with rabbit skeletal muscle actin and bovine brain tubulin; however, specific assays used to separate actin from whole-cell preparations gave ambiguous results. Ultrastructural studies revealed the presence of extracellular material between the raphe canal and the substratum in motile cultures. An assay was devised for the detection of radioactively labeled material (MW 〉 1800 Daltons) released by motile cultures into the culture medium. When cultures were treated with either an anticytoskeletal drug or monensin, motility was inhibited while the amount of measured radioactivity increased over solvent-treated control groups. The results from this study indicate possible roles for both actin- and tubulin-based structures in gliding motility of Amphora. Though secretion may be necessary for gliding to occur, its exact relationship to motility was not deduced. The data obtained in this study are compatible with a theory for the mechanism of gliding which involves the surface translocation of externally exposed membrane proteins against an immobile matrix of substratum-attached secreted material to generate the force required for movement.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0886-1544
    Keywords: chemotaxis ; cell motility ; cellular polarity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Amebae of Dictyostelium discoideum normally chemotax to aggregation centers by assessing the direction of outwardly moving, nondissipating waves of the chemoattractant cAMP. However, D. discoideum amebae can also assess the direction of a relatively stable spatial gradient. We demonstrate that amebae migrating towards the “source” of a stable, spatial gradient move faster, extend fewer pseudopodia, and turn less frequently than amebae migrating away from the “source” in the same spatial gradient. In addition, amebae extend lateral pseudopods in a polarized fashion from the anterior half of the cell, and do so as frequently towards the source as away from the source. However, those formed towards the source more often produce a turn than those formed away from the source. These results suggest that there may be two decision-making systems, one localized in the pseudopods, and one along the entire cell body; they support the suggestion that Dictyostelium amebae may employ a temporal mechanism to assess the direction of a spatial gradient of chemoattractant.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 7 (1987), S. 361-367 
    ISSN: 0886-1544
    Keywords: Cell Analyzer ; cell motility ; temperature ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The phenomena of mammalian cell motility in tissue culture is an integrated function of many cellular components. As such, cell motility is very sensitive to external stimuli and perturbation. In this article we report the effect of temperature in the range 33°C to 39°C on cell motility. For this 3T3 cells were plated in plastic tissue culture flasks. A large number of individual cells (60 per experiment) were tracked as a function of time by means of an automated device, the Cell Analyzer. The data show a peak in the average cell speed in the range 36.5°C to 38.5°C, falling off sharply at lower and higher temperatures. The average rate of cell motility closely correlates to the average cell proliferation rate in the range 33°C to 39°C.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 19 (1985), S. 161-178 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The patency of heparin-polyvinyl alcohol (hep-PVA) coated polyethylene tubing was found to be significantly longer than control tubes coated with polyvinyl alcohol (PVA) but without heparin at low flow rates in dogs using a novel parallel flow arteriovenous shunt designed to avoid surgical artifacts. A standard Silastic chronic shunt (3.18 mm i.d.) was inserted between the iliac artery and vein of a dog. After a 2-week recovery period, a small diameter coated polyethylene tube (1.14 mm i.d.) was connected in parallel with the exteriorized portion of the chronic shunt through a pair of Silastic Y-connectors, so that 〈3% of the shunt flow was diverted into the test tube. The chronic shunt was reused many times over a 〉6 month patency period, eliminating the need for frequent surgery and reducing interanimal variability in the results. The difference in patency between heparinized and control tubes was greater at higher mainshunt flow rates indicating the presence of a significant effect of the Y-connectors on platelet adhesion or aggregation. This effect was manifested in a time-dependent reduction in circulating platelet count. Scanning electron microscopy (SEM) examination of the midportion of the heparinized tubes after occlusion demonstrated the absence of platelet and fibrin deposits, unlike the control tubes without heparin. Although the Y-connectors played a significant role, they did not dominate the thrombotic processes occurring in this shunt and consequently the biological effectiveness of the immobilized heparin could be demonstrated.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 19 (1985), S. 179-193 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: As a series of studies on the mechanical properties of materials used in cardiac prostheses, static and dynamic characteristics and stability of five kinds of elastomeric polymers have been studied by uniaxial tensile and fatigue tests in air at room temperature and in saline solution at 37°C. Of all materials tested in this study, Texin MD85A, a segmented polyether polyurethane, has the lowest flexibility under static and dynamic conditions, with relatively high strength. Hexsyn, a polyolefin rubber, is highly flexible with little stress relaxation. However, this material has very low tensile strength and short elongation, and shows unstable change in the elastic modulus during cyclic deformation. Avcothane 51, a copolymer of polyurethane and silicon, has unstable mechanical properties and gradually stiffens upon cyclic deformation. On the other hand, Biomer, a segmented polyether polyurethane, has high flexibility and shows the most stable behavior during cyclic deformation regardless of test environment. Toyobo TM5, a similar segmented polyurethane to Biomer, has higher strength and ductility than Biomer, although its static and dynamic flexibility are slightly worse and less stable than those of Biomer. These results indicate that Biomer and Toyobo TM5 are more suitable for flexible components of cardiac prostheses.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 19 (1985), S. 197-198 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 19 (1985), S. 241-250 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: This is a review of the surface chemistry of bone mineral and its synthetic counterpart hydroxypapatite. Small-angle x-ray scattering and low-temperature nitrogen adsorption measurements show bone mineral surfaces range from 100 to 200 m2/g. The heats of adsorption of small molecules on bone and apatite surfaces show that these materials have polarizing surfaces which form strong bonds with polar and polarizable molecules. Water is hydrogen bonded to these surfaces with energies ranging from 23 Kcal/mol, for low coverage, to 11 Kcal/mol after two full layers; the latter value shows that after two monolayers the water is bonded as strongly to the solution as it is to the apatite surface. Stearic acid in cyclohexane adsorbs on bone and apatite surfaces in a closed-packed manner with the straight-chain molecules in parallel array with the end carboxyl groups hydrogen bonded to surface electronegative ions. Synthetic hydroxyapatite has long been used in chromatography because of the bonding capacity apatite surface has for certain proteins and polynucleotides. The metabolic interplay between bone mineral and the body results from the high magnitude and high reactivity of the mineral surface.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...