ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Analytical Chemistry and Spectroscopy  (963)
  • Life and Medical Sciences  (575)
  • 1980-1984  (1,538)
  • 1981  (1,538)
Collection
Keywords
Publisher
Years
  • 1980-1984  (1,538)
Year
  • 1
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010408
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010409
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 111 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010405
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010403
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010308
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    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 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040509
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040510
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040603
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040605
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    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.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040607
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040308
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Inhibition of acrosin by oviductal secretory immunoglobulin A (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 15-23 
    Details
    ISSN: 0148-7280
    Keywords: secretory IgA ; oviduct fluid ; acrosin ; spermatozoa ; fertilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A major inhibitor of acrosin in rhesus monkey and rabbit oviduct fluid, isolated by isoelectrofocusing in sucrose gradients, displayed a broad peak in the acidic region of the column and was demonstrated to contain secretory IgA specific for acrosin. Its identity was established by immunodiffusion, by the removal of acrosin inhibition with antisera to IgA (α-chain), and by its correct molecular weight during ultracentrifugation. Purified human serum IgA also inhibited rabbit, rhesus monkey, and human acrosins, but neither purified human IgG nor IgM had any inhibitory effect on these acrosins. Neither oviduct fluid secretory IgA nor purified human serum IgA inhibited the activity of bovine pancreatic trypsin. The high specificity of secretory IgA for acrosin and its presence in every rabbit and rhesus monkey oviduct fluid specimen examined suggests a possible regulatory role for this antibody in reproduction.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Factors which may affect removal of protamine from sperm DNA during fertilization in the rabbit (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 25-34 
    Details
    ISSN: 0148-7280
    Keywords: fertilization ; pronuclei ; chromatin decondensation ; protamine ; kinase ; glutathione reductase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In order to derive information about possible mechanisms by which the sperm head is converted into the male pronucleus during fertilization in the rabbit, unfertilized egg homogenate was assayed for two enzyme activities. Protamine was extracted from rabbit sperm, purified, and labelled with [14C] in an in vitro reaction and used as a probe to assay for a protein kinase which could transfer [32P]PO4 from [γ-32P]ATP onto the substrate. A kinase with a pH optimum of approximately 8.0 to 8.5 is described. Assays for the enzyme glutathione reductase were performed using homogenates from eggs or embryos at three early stages of development. Results suggest that oocytes can oxidize 2.58 × 10-6 μmol NADPH per minute per oocyte, unfertilized eggs 5.16 × 10-7 μmol NADPH per minute per ovum, and 20- to 24-hour postcoitus fertilized eggs 2.30 × 10-6 μmol NADPH per minute per ovum. The relevance of these observations to male pronuclear formation is discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Induction of meiosis of Xenopus laevis oocytes by mianserine (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 49-56 
    Details
    ISSN: 0148-7280
    Keywords: meiotic maturation ; progesterone ; mianserine ; oestradiol ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Maturation of Xenopus laevis oocytes can be induced by mianserine, a tricyclic antidepressant. K+-free medium facilitates this maturation process. Mianserine must be kept in contact with the oocytes during the whole process of maturation for maximal efficiency. It is inactive after injection into the oocytes. Mianserine induces the formation of maturation-promoting factor (MPF) in the treated oocytes. Mianserine-induced maturation is strongly inhibited by theophylline, even in K+-free medium. Progesterone displays synergistic effects with mianserine for the induction of maturation. Likewise, oestradiol shows cooperative maturing effects with progesterone as well as with mianserine. It is suggested that mianserine exerts its primary effects on oocyte maturation by inhibiting a membrane adenylate cyclase.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    The spermatogenesis of crustaceans. VII. Review of spermatozoon of the crayfish Astacus astacus (Malacostraca, Decapoda, Macrura, Reptantia) (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 65-82 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoon-crayfish (Astacus astacus) ; ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The star-like spermatozoon of Astacus astacus consists of a spheroidal central body around which various prolongations of same, denominated spines, are arranged. In the interior of the gamete the following parts may be distinguished: (1) The acrosomic region, formed by a complex vesicle, or thick-walled, helmetshaped body, whose opening is orientated towards the nuclear region. In the interior of the vesicle different structures can be appreciated. (2) The nuclear region, which is formed by a large cupuliform nucleus limited by a double membrane. In the nucleoplasm numerous bundles of microtubules, mixed with noncondensated chromatin fibers, are found. (3) The laminar region, present in other Decapoda, is practically nonexistent. Within the spines of these spermatozoa, only microtubules can be observed. The morphology of this crayfish is similar to that presented by Brachiura, another group of Reptantia.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Kinematics of human spermatozoa (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 83-95 
    Details
    ISSN: 0148-7280
    Keywords: human spermatozoa ; flagellum ; motion ; microcinematography ; kinematics ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A microcinematographic (50 f/s) study was performed on motile human spermatozoa. Eighty percent were found to have a linear trajectory and a pseudo-sinusoidal head displacement pattern. Throughout their progression, the spermatozoa periodically rotated on their longitudinal axis at a frequency equal to that of flagellar wave formation. These waves were found always to begin on the same side of the cell and to propagate in the flattened plane of the head until the moment of rotation. At this time the wave had reached a point near the middle of the flagellum. Beyond this point, the flagellum moves out of the plane of the head. Different variables used to characterize the movement of spermatozoa included the velocity of progression, amplitude and velocity of head displacement, frequency of rotation, wave amplitude, and propagation velocity of the flagellar wave. Among these variables, it was the propagation velocity of the wave that was found to be best correlated with the velocity of spermatozoan progression. This flagellar wave exhibited two stages, one of initiation and one of propagation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    The assessment of human sperm morphology in surface replica preparations for transmission electron microscopy (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 113-119 
    Details
    ISSN: 0148-7280
    Keywords: human spermatozoa ; morphology ; semen analysis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Human spermatozoa were treated with the detergents Hyamine 2389, Triton X-100, or sodium dodecyl sulphate (SDS) and surface replica preparations and Papanicolaou-stained smears made. From the ultrastructural studies it was found that Hyamine caused a dissolution of the plasmalemma to reveal the outer acrosomal membrane that was often absent over the anterior cap region; whereas Triton, in addition, caused severe damage to the entire acrosome. Treatment with SDS rapidly cleaved the tails from the majority of the spermatozoa, stripped the plasmalemma from both the head and tail regions of the cells, and also removed the whole of the outer acrosomal membrane plus most of the acrosomal contents. However, when viewed in the Papanicolaou-stained preparations, the spermatozoa were all of apparently normal morphology.These studies make it clear that some caution must be used when interpreting human sperm morphology assessments made under the light microscope. While it is not suggested that the more involved technique of surface replication should be used in routine semen analyses, it does represent a valuable technique for use with research material.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Inhibition of fertilization in cattle by passive immunization with anti-zona pellucida serum (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 133-138 
    Details
    ISSN: 0148-7280
    Keywords: inhibition of fertilization ; bovine zonae pellucidae ; passive immunization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Passive immunization with antiserum prepared against isolated bovine zonae pellucidae inhibited fertilization in the cow. The minimum dosage of antiserum (titer 27 by immunofluorescence) required for complete inhibition was 2 ml/kg of body weight.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    How is polyspermy prevented? (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 151-169 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040209
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    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.1120040301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Sperm abnormalities in the PL/J mouse strain: A description and proposed mechanism for malformation (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 171-183 
    Details
    ISSN: 0148-7280
    Keywords: mouse ; spermatogenesis ; sperm differentiation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A high frequency (42%) of sperm from the inbred homozygous mouse strain PL/J are abnormal. Head shape abnormalities occur in 15% of the total sperm; and 27% of the sperm are headless, with the mitochondria condensed into a mass at the caudal end of the midpiece region. The sperm without heads exhibit relatively normal motility. Electron microscopy of the testes indicates that some of the abnormal sperm in PL/J males result from a failure of the paired centrioles to attain a normal position on the nucleus opposite the acrosome prior to implantation, or to attach at all. The centrioles that are not attached to the nuclear envelope can differentiate to form the principal piece and midpiece region. The frequency of headless variants in heterozygous F1 indicates that the trait is mainly recessive. The offspring from the backcross of the F1 to homozygous PL/J parents did not give a clear-cut segregation pattern. The frequency of abnormal sperm in the F1 and the backcross is higher when the female parent is a PL/J.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Vitelline layer lytic activity in sperm extracts of sea urchin, Hemicentrotus pulcherrimus (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 193-202 
    Details
    ISSN: 0148-7280
    Keywords: lysin ; protease ; sperm ; sea urchin ; vitelline layer ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A factor which dissolves the vitelline layer was extracted from sperm of the sea urchin, Hemicentrotus pulcherrimus. Turbidity of the suspension was reduced when isolated vitelline layers were mixed with this sperm factor. When the mixture was subjected to SDS polyacrylamide gel electrophoresis, some of the protein bands of the vitelline layer were seen to be missing. The lytic activity of the factor was heat labile, completely inhibited by L-1-tosyl-amide-2-phenyl-ethylchloromethyl ketone and partially inhibited by soybean trypsin inhibitor. Chymotrypsin activity was detected, but not trypsin, arylsulfatase, or glycosidase. These results suggest that a chymotrypsin-like enzyme participates in lysis of the vitelline layer by the fertilizing spermatozoon.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Inhibition of the metabolism of ram spermatozoa by derivatives of α-chlorohydrin (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 203-217 
    Details
    ISSN: 0148-7280
    Keywords: α-chlorohydrin ; antifertility agent ; ram ; sperm metabolism ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The effects of the male antifertility agent, α-chlorohydrin, six of its derivatives, and glycidol were studied on the metabolism of washed ram spermatozoa in vitro with fructose as substrate. The α-chlorohydrin derivatives were the amino, the phosphorylated, and four glycol-bridge (ketal) compounds. All compounds except glycidol, in a concentration between 0.1 and 100 mM, reduced the aerobic glycolsis and/or oxidation of fructose. However, there was not a high correlation between the ability of these compounds to inhibit the metabolism of ram spermatozoa in vitro and their antifertility activity when administered to male rats. Other factors are clearly involved in their antifertility activity, eg, the concentration of the compounds in the epididymis and their conversion of either more or less spermicidal compounds in the body.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Monoclonal antibodies. Hybridomas: A new dimension in Biological Analyses. Roger H. Kennett, Thomas J. McKearn and Kathleen B. Bechtol, Eds., Plenum, New York, 1980. 20 illustrated chapters, appendix, and index. 423 pages. $29.50 (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 251-252 
    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.1120040309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Effect of anti-pig zona pellucida serum on fertilization in several mammals (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 231-239 
    Details
    ISSN: 0148-7280
    Keywords: inhibition of fertilization ; pig zonae pellucidae ; passive immunization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The effect of goat antiserum against isolated pig zonae pellucidae on fertilization in vivo was examined in the pig, cow, sheep, rabbit, rat, and mouse. As shown by indirect immunofluorescence, anti-pig zona serum reacted strongly with the zonae of pig, cow, sheep, and rabbit, but the reaction with the zonae of mouse and rat was weak. Passive immunization with anti-pig zona serum significantly, or completely, inhibited fertilization in all species. However, inhibition of fertilization was more pronounced in the pig, cow, sheep, rabbit, and mouse than in the rat. Inhibition of fertilization in the rabbit was also observed after passive immunization with antiserum absorbed with rabbit liver and kidney. All of the zonae recovered from the pig, cow, sheep, rat, and mouse after passive immunization with anti-pig zona serum exhibited strong fluorescence, regardless of the incidence of fertilization. It was concluded that the pig and other mammalian zonae pellucidae tested have tissue-specific antigens.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Other Books Received (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 252-252 
    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.1120040310
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    The movement characteristics of rabbit spermatozoa before and after activation (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 275-282 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoa ; activation ; oviduct ; sperm movements ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Spermatozoa were flushed with mineral oil from the lower isthmus of the rabbit oviduct at four hours postcoitus (pc) and 11 hours pc. Videotapes were made of sperm behavior in the native isthmic fluid and after dilution of the fluid with culture medium. The tapes showed that, initially, spermatozoa in the native isthmic fluid were virtually immotile, but immediately resumed movement on contact with the culture medium. Isthmic sperm motility then evolved over a five- to 10-minute interval into the characteristic biphasic pattern of activated movement. Cine films of isthmic spermatozoa taken with a high-speed camera were analyzed to determine flagellar beat frequency, maximum flagellar curvature, and swimming velocity. Progressiveness ratios and hydrodynamic power outputs were then calculated for individual spermatozoa. Two phases of activated sperm movement, a whiplash phase and a progressive phase, were identified and characterized. The power output of activated spermatozoa increased twentyfold in comparison with the preactivated state. The power output of activated spermatozoa did not differ between the two phases of activated movement.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040403
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Organization of mitochondrial DNA in normal and texas male sterile cytoplasms of maize (1981)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 2 (1981), S. 319-336 
    Details
    ISSN: 0192-253X
    Keywords: maize ; mitochondrial DNA ; recombinant DNA ; cms-T ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Recombinant DNA and hybridization techniques have been used to compare the organization of mitochondrial DNA (mtDNA) from normal (N) and Texas male sterile (T) cytoplasms of maize. Bam H1 restriction fragments of normal mtDNA were cloned and used in molecular hybridizations against Southern blots of Bam H1 digested N and T mtDNA. Fifteen of the 35 fragments were conserved in both N and T as indicated by hybridization to comigrating bands in their restriction patterns. Only three fragments produced autoradiographs whose differences could reasonably be attributed to single changes in the cleavage site of the enzyme while approximately half (17/35) of the clones resulted in more complicated differences between N and T. The autoradiographs produced by these 17 clones indicated multiple cleavage site changes and/or sequence rearrangements of the mtDNA. Patterns of six of these 17 clones indicated partial duplication of the sequence and two showed variation in the intensity of hybridization between N and T, which may be related to the molecular heterogeneity phenomenon found in maize mitochondrial genomes. The large proportion of changes observed between N and T mtDNA indicates that rearrangements may have played an important role in the evolution of the maize mitochondrial genome.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020020402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Induction of the shift in melanin synthesis in lethal yellow (Ay/a) mice in vitro (1981)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 2 (1981), S. 349-356 
    Details
    ISSN: 0192-253X
    Keywords: agouti locus ; lethal yellow gene ; MSH ; dibutyryl cyclic AMP ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Alleles at the agouti locus determines the type of pigment produced in hair-bulb melanocytes. In order to analyze the mechanism of agouti gene function, an attempt was made to induce the shift in melanin synthesis in vitro. Skin explants from newborn yellow mice with genotype Ay/a were cultured with the method using membrane-filter and roller tube. Production of black pigment in the hair bulbs was observed when the explants were cultured in the presence of α-melanocyte stimulating hormone (α-MSH). Electron-microscopic observation indicates that the induced black pigments are eumelanin that is normally found in hair-bulb melanocytes of genotypically black mice. The eumelanin synthesis was also induced by cAMP, DbcAMP, or theophylline. This α-MSH-induced eumelanin synthesis was suppressed by actinomycin D or cycloheximide, suggesting that the α-MSH-induced eumelanogenesis requires de novo transcription and/or translation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020020404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Equalizing the electric field intensity within chick brain immersed in buffer solution at different carrier frequencies (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 411-413 
    Details
    ISSN: 0197-8462
    Keywords: calcium efflux ; complex permittivity ; amplitude windows ; concentric spheres ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Presented here are the numerical relationships between incident power densities that produce the same average electric field intensity within a chick brain half immersed in buffered saline solution and exposed to a uniform electromagnetic field at carrier frequencies of 50, 147, and 450 MHz. Calculations are based on modeling the buffer solution as a spherical shell in air with an inner concentric sphere of brain tissue. The results support our earlier conclusion that calcium efflux results obtained at different carrier frequencies are in agreement when related by the electric field within the brain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020413
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Biological effects of oscillating electric fields: Role of voltage-sensitive ion channels (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 23-32 
    Details
    ISSN: 0197-8462
    Keywords: biological effects of oscillating electric fields ; excitable cells ; voltage-sensitive ion channels ; gating charges ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: An alternating component of potential across the membrane of an excitable cell may change the membrane conductance by interacting with the voltagesensing charged groups of the protein macromolecules that form voltage-sensitive ion channels. Because the probability that a voltage sensor is in a given state is a highly nonlinear function of the applied electric field, the average occupancy of a particular state will change in an oscillating electric field of sufficient magnitude. This “rectification” at the level of the voltage sensors could result in conformational changes (gating) that would modify channel conductance. A simplified two-state model is examined where the relaxation time of the voltage sensor is assumed to be considerably faster than the fastest changes of ionic conductance. Significant changes in the occupancy of voltage sensor states in response to an applied oscillating electric field are predicted by the model.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Flight, orientation, and homing abilities of honeybees following exposure to 2.45-GHz CW microwaves (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 71-75 
    Details
    ISSN: 0197-8462
    Keywords: honeybees ; invertebrates ; behavior ; solar power satellite ; 2.45-GHz microwaves ; continuous wave ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Foraging-experienced honeybees retained normal flight, orientation, and memory functions after 30 minutes' exposure to 2.45-GHz CW microwaves at power densities from 3 to 50 mW/cm2. These experiments were conducted at power densities approximating and exceeding those that would be present above receiving antennas of the proposed solar power satellite (SPS) energy transmission system and for a duration exceeding that which honeybees living outside a rectenna might be expected to spend within the rectenna on individual foraging trips. There was no evidence that airborne invertebrates would be significantly affected during transient passage through microwaves associated with SPS ground-based microwave receiving stations.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Dielectric properties of animal tissues in vivo at frequencies 10 MHz - 1 GHz (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 93-103 
    Details
    ISSN: 0197-8462
    Keywords: permittivity ; in vivo ; radio frequencies ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: An open-ended coaxial line sensor in conjunction with an automatic network analyzer was used to measure in vivo the permittivity of several feline tissues (skeletal and smooth muscle, liver, kidney, spleen, and brain - gray and white matter) at frequencies between 10 MHz and 1 GHz. The estimated uncertainties of measurement were between 1.5% and 5%. The data are in general agreement with previously obtained data in vitro and in vivo. Significant differences in the properties of different types of the same tissue (eg, skeletal and smooth muscle) were observed. Many tissues were found to be non-homogeneous in its permittivity.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Effects of millimeter-wave radiation on monolayer cell cultures. II. Scanning and transmission electron microscopy (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 141-150 
    Details
    ISSN: 0197-8462
    Keywords: millimeter-wave radiation ; BHK-21/C13 cells in monolayer culture ; scanning electron microscopy ; transmission electron microscopy ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Both thermal and athermal effects of millimeter-wave radiation on BHK-21/C13 cells were sought using scanning and transmission electron microscopy in conjunction with an in vitro technique that allows direct exposure of monolayer cultures to high average power densities. Culture dishes were irradiated by placing them on the open end of an E- or U-band wave guide. This technique exposes different regions of the cell monolayer lying along the longer axis of the wave guide aperture to varying power densities ranging from zero at each edge to twice the average power density at the center.Cell ultrastructure was unaffected by microwave radiation for 1 hour (41.8 or 74.0 GHz, average power densitites = 320 or 450 mW/cm2, respectively) with or without cooling by rapid recirculation of the culture medium. Temperature in recirculated cultures was held at 37.2 °C, and that in noncooled cultures never exceeded 42 °C during irradiation at either power density. In contrast, cell morphology was affected by microwave exposure whenever irradiation conditions were altered so that the temperature of the monolayer reached or exceeded 44.5 °C. Ultrastructural alterations included breakage of cell processes, progressive detachment of cells from the substrate, increased clumping of heterochromatin in the nuclei, and the appearance of large empty vesicles in the cytoplasm. Such morphological changes resulted from either application of higher average power densities or irradiation at the power densities described above at a higher ambient temperature (〉38.5°C).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Effect of homogeneous magnetic fields on responses to toxic stimulation in spirostomum ambiguum (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 187-198 
    Details
    ISSN: 0197-8462
    Keywords: ciliated protozoan ; DC magnetic field ; calcium-mediated contraction ; motility ; 2,2′-dipyridyldisulfide ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Effects of DC magnetic fields, up to 125,000 G, on the survival of the ciliated protozoan Spirostomum ambiguum exposed to the toxic substance 2,2′-dipyridyldisulfide are reported. The magnetic field diminishes the ability of the organism to survive the drug, and lengthens the extension phase of the contraction cycle. It is proposed that the magnetic field alters the regulation of intracellular (C2+) transients.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020209
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Development of xenopus laevis embryos in a static magnetic field (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 199-201 
    Details
    ISSN: 0197-8462
    Keywords: static magnetic fields ; development ; frog embryos ; low temperature ; cell membranes ; lipid phase transition ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Xenopus laevis embryos were exposed to a DC magnetic field (2.5 kG) for periods up to 1 week. The previously reported stabilization of cell membranes by stationary magnetic fields could not be demonstrated.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020210
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Comparison of RF-induced calcium efflux from chick brain tissue at different frequencies: Do the scaled power density windows align? (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 407-409 
    Details
    ISSN: 0197-8462
    Keywords: calcium efflux ; complex permittivity ; amplitude windows ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The recent suggestion that the pattern of positive and negative results of RF-induced calcium efflux from chick brain tissue, when appropriately scaled, matches at three frequencies is examined. Close scrutiny of this recently reported analysis by Joines and Blackman suggests that the uncertainties in the calculated scaling quantities are too large to permit meaningful conclusions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020412
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Effect of nonionizing radiation on the purkinje cells of the rat cerebellum (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 247-257 
    Details
    ISSN: 0197-8462
    Keywords: nervous system ; rat cerebellum ; nonionizing radiation ; Purkinje cells ; microwaves ; radiofrequency ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: In one experiment, Sprague Dawley rats (16-21 days of gestation) and their offspring were exposed to 100-MHz (CW) electromagnetic radiation at 46 mW/cm2 (SAR 2.77 mW/g) for 4 h/day for 97 days. In another experiment, the pregnant rats were irradiated daily from 17 to 21 days of gestation with 2450-MHz (CW) microwaves at 10 mW/cm2 (SAR 2 mW/g) for 21 h/day. In a third experiment, 6-day-old rat pups were irradiated 7 h/day for five days with 2450-MHz radiation at 10 mW/cm2. Equal numbers of animals were sham irradiated in each group. Quantitative studies of Purkinje cells showed a significant and irreversible decrease in rats irradiated during fetal or fetal and early postnatal life. In animals exposed postnatally, and euthanized immediately after irradiation, significant decrease in the relative number of Purkinje cells was apparent. However, restoration apparently occurred after forty days of recovery.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    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.1120040201
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Radiofrequency electromagnetic fields in swedish radio stations and tall FM/TV towers (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 61-69 
    Details
    ISSN: 0197-8462
    Keywords: FM radio broadcast ; VHF-TV broadcast ; UHF-TV broadcast ; electromagnetic field strengths ; personnel hazard ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Radiofrequency electric and magnetic fields have been measured around 11 large broadcast stations and tall FM/TV towers in Sweden. The results show that operating personnel may be exposed to fields exceeding by several times the present standard for occupational exposure to RF radiation. Maintenance personnel are especially vulnerable to exposure when climbing energized towers. The present study indicates that the transmitters should be switched off during the performance of certain tasks on the tower. Safe passage of maintenance personnel near energized antennas of certain types is impossible without a drastic reduction of the transmitted power. In the stations, the RF leakage radiation was generally low, but when work was done with the cabinet doors of the transmitter open, high field strengths were found in the vicinity of the transmitter even though it was switched off. It was found that the transmitter acted as a tuned receiver of energy from the other transmitters.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Microwave-induced increase of water and conductivity in submaxillary salivary gland of rats (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 51-60 
    Details
    ISSN: 0197-8462
    Keywords: 2880-MHz microwaves ; rats ; submaxillary salivary gland ; thermoregulation ; tissue conductivity ; tissue hydration ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Hypersalivation is an important mechanism for heat dissipation by animals without sweat glands. The water content and conductivity (at 20 kHz) in sub-maxillary salivary gland (SSG) and in other tissues were investigated in adult male rats exposed to microwaves (2880 MHz, 1.5 μs pulses at 1000 Hz) or to conventional heat at 40 °C. Eighty rats in one series were exposed, one at a time, for 30 min to microwaves producing a specific absorption rate (SAR) of 4.2,6.3,6.8,8.4,10.8 or 12.6 W/kg. Fifty rats were sham-exposed under similar environmental conditions. In the second series, ten rats were sham-exposed, 33 rats were exposed, one at time, for 15, 30 or 60 min to microwaves at a SAR of 9.5 W/kg, and 32 rats were exposed for similar periods to conventional heat at 40 °C. In rats of the first series colonic temperatures were elevated significantly at a SAR of 4.2 W/kg, while SSG water content and conductivity increased significantly at SAR values of 6.3 W/kg and higher. In the second series of experiments increases in colonic temperature and SSG water content were greater after 15 and 30 min of microwave exposure than after exposure to heat. Also, SSG conductivity was significantly depressed by heat and significantly increased by microwaves after exposure for 15 or 30 min. The results support the hypothesis that water content and conductivity of SSG of rats can be used as a sensitive specific test of a microwave induced thermal response.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Possible humoral mechanism of 2450-MHz microwave-induced increase in complement receptor positive cells (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 81-84 
    Details
    ISSN: 0197-8462
    Keywords: 2450-MHz microwaves ; complement receptors ; diffusion chambers ; soluble factors ; immune system ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: These studies indicate that the increase in the frequency of complement receptor-positive (CR+) spleen cells observed 6 days after a 30-min exposure to 2450-MHz microwaves is not the result of microwave-induced alterations of lymphocyte recirculation patterns, but is mediated by a soluble, humoral factor produced by cells within the spleen.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Endocrinological effects of strong 60-Hz electric fields on rats (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 105-121 
    Details
    ISSN: 0197-8462
    Keywords: 60-Hz electric fields ; ELF radiation ; rat endocrinology ; organ weights ; hormones ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Adult male rats were exposed or sham-exposed to 60-Hz electric fields without spark discharges, ozone, or significant levels of other secondary variables. No effects were observed on body weights or plasma hormone levels after 30 days of exposure at an effective field strength of 68 kV/m. After 120 days of exposure (effective field strength = 64 kV/m), effects were inconsistent, with significant reductions in body weight and plasma levels of follicle-stimulating hormone and corticosterone occurring in one replicate experiment but not in the other. Plasma testosterone levels were significantly reduced after 120 days of exposure in one experiment, with a similar but not statistically significant reduction in a replicate experiment. Weanling rats, exposed or sham-exposed in electric fields with an effective field strength of 80 kV/m from 20 to 56 days of age, exhibited identical or closely similar growth trends in body and organ weights. Hormone levels in exposed and sham-exposed groups were also similar. However, there was an apparent phase shift between the two groups in the cyclic variations of concentrations of hormones at different stages of development, particularly with respect to follicle-stimulating hormone and corticosterone. We concluded that 60-Hz electric fields may bring about subtle changes in the endocrine system of rats, and that these changes may be related to alterations in episodic rhythms.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    In vitro study of microwave effects on calcium efflux in rat brain tissue (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 161-167 
    Details
    ISSN: 0197-8462
    Keywords: microwave effects on CNS ; pulsed microwaves ; brain calcium efflux ; 1 GHz ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: In this study we investigated the prospect of microwave-induced alteration of 45Ca2+ efflux from rat neural tissue at low pulse repetition frequencies and low power densities under in vitro conditions. Rat cerebral tissue, preloaded with 45Ca2+, was exposed to pulsed-microwave radiation (1-GHz carrier frequency) according to one of several PRF-power density exposure schemes: 16 Hz at 0.5, 1.0, 2.0, or 15 mW/cm2, or 32 Hz at 1.0 or 2.0 mW/cm2 average power density. Measurements of radioactivity in the efflux medium and in the tissue sample were used to calculate an efflux value for each sample. The results indicate that the radiation conditions used did not alter calcium efflux in rat brain tissue.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Masthead (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981) 
    Details
    ISSN: 0197-8462
    Keywords: Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Prolonged microwave irradiation of rats: Effects on concurrent operant behavior (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 169-185 
    Details
    ISSN: 0197-8462
    Keywords: microwave radiation ; pulse modulation ; waveguide exposure ; chronic exposure ; operant behavior ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Two measures of performance were used to study the effects of pulse-modulated microwave radiation (PM MWR) on schedule-controlled operant behavior of rats: 1) cued (SD), fixed-ratio (FR) bar pressing for food reinforcement; and 2) noncued (Sd) bar pressing in the absence of food reinforcement. The animals were irradiated and the behavioral data were obtained concurrently, during daily three-hour sessions, five days per week for six to nine weeks. Each experiment began with a two to three-week baseline interval of sham irradiation; a two to three-week interval of sham irradiation followed the irradiation phase. The irradiated animals were exposed to 1.3-Ghz PM MWR (pulse width of 1 microsecond at 600 pulses per second) at whole-body, average specific absorbed-dose rates of from 1.5-6.7 mW/g. Control and irradiated animals were tested in identical, cylindrical waveguide exposure/behavioral assemblies; different groups of irradiated and sham-irradiated animals were used for each dose rate. At 1.5 mW/g, the levels of SD operant responding by control and irradiated animals were comparable, and showed similar progressive diminutions over the course of each daily session. Sd operant responding was more variable, but again comparable, with both groups showing similar, progressive declines in rate of responding during each session. At 3.6 mW/g, no specific effects on SD operant response rates were observed. However, there was an initial and transient increase in the rate of extinction of Sd responding. At 6.7 mW/g, SD response rates were slightly reduced, whereas there was a major reduction in noncued (Sd) operant responding followed by a sharp rebound during the first post-MWR week. This marked reduction in Sd operant responding at MWR onset was in contrast to the relative stability and persistence of FR responding for food reinforcement.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Transbilayer movement of 24Na in sonicated phosphatidylcholine vesicles exposed to frequency-modulated microwave radiation (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 217-225 
    Details
    ISSN: 0197-8462
    Keywords: lipid vesicles ; Na+ leakage ; 2450 MHz ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Sonicated egg phosphatidylcholine vesicles loaded with 24Na+ were exposed at 20mW to a frequency-modulated (3 Hz) microwave field in the range of 2350 to 2550 MHz, or at 80 mW to a 2450-MHz CW (continuous wave) field, in a waveguide. The vesicle suspension absorbed microwaves at about 1 mW/ml and 25 mW/ml (CW experiment). The average temperature change of the irradiated suspension was 〈 0.1 °C from ambient. Leakage of 24Na+ from the vesicles for up to 19 hours was measured. No difference was noted in the movement of 24Na+ from the vesicles in the irradiated and control dispersions.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    General properties of the interaction between animals and ELF electric fields (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 1-11 
    Details
    ISSN: 0197-8462
    Keywords: electric fields ; 60-Hz ; biological effects ; dosimetry ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: An analysis is given of the interaction between extremely low-frequency (ELF) electric fields and animals of arbitrary body shape. This analysis is based on three approximations which are valid in the ELF range: In living tissues, capacitive (displacement) currents are negligible compared to conduction currents; effects resulting from the finite velocity of propagation of electromagnetic fields are negligible; skin effect in living tissues is negligible. Major conclusions of the analysis are: (a) The electric field outside the body, the induced charge on the surface of the body, and the total current crossing any section through the body (eg, through the neck or limbs) are completely determined by the characteristics of the applied ELF electric field, the shape of the body, its location relative to ground and other conductors, and any conduction currents from the body to ground or other conductors. (b) All of the quantities in (a) can be measured using conducting animal models. (c) The magnitudes of the electric field outside the body and the induced charge density on the surface of the body are independent of frequency, in the ELF range, when the body is either insulated from or shorted to ground (and any other conductors in the system). (d) The only quantities affected by the electrical properties of the tissues comprising the body are the current density and electric field inside the body. (e) The electric field outside and inside a body will be unchanged by a scaled change in its size.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Interactive effects in 60-HZ electric-field exposure systems (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 33-50 
    Details
    ISSN: 0197-8462
    Keywords: electric fields ; 60-Hz ; dosimetry ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The level of exposure of laboratory animals to 60-Hz electric fields is commonly specified in terms of the unperturbed field strength present before the introduction of experimental subjects and their cages. In the research reported in this paper, rats were housed in two parallel rows of 12.4 cm × 25.1 cm × 10.2 cm high plastic cages resting on the lower electrode of a parallel-plate exposure system, and the actual perturbed electric fields experienced by an experimental animal were investigated. The most important results are: 1) Reducing the spacing between the exposure electrodes from 8.7 to 1.7 times the height of a singly exposed rat model, while maintaining a constant unperturbed field strength, resulted in a 15% increase in the electric field at the highest point on the surface of the body and a 10% increase in the short-circuit current of the model. 2) For multiple animal exposures, increases of 10% in both the field at the highest point of the body and the short-circuit current were observed when the electrode spacing was reduced from 8.7 to 2.6 times the height of a rat. 3) Plastic cages caused 1 - 6% reductions in the electric field at the surface of the body, except very near the cage walls, where enhancements of more than 20% were observed. 4) When 16 rats were simultaneously exposed, the short-circuit current, Is, of an individual subject of weight W (in g), that was surrounded on all sides by other rats of weight W, was reduced from the short-circuit current, Iu, measured with the same subject individually exposed as follows: during a 12 h light (sleeping) cycle, Is/Iu = 1.00 - 0.0173W1/2; during a 12 h night (awake) cycle, Is/Iu = 1.00 - 0.0136W1/2.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Microwave treatment of intracerebral l1210 leukemia: Schedule-dependent partial reversal of the effects of methotrexate (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 77-80 
    Details
    ISSN: 0197-8462
    Keywords: microwaves ; L1210 leukemia ; central nervous system ; methotrexate ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: One-GHz microwave (MW) irradiation at a power density of 5 mW/cm2 was combined with methotrexate (MTX) in an attempt to treat more effectively central nervous system (CNS) L1210 leukemia in DBA/2J mice. When mice with CNS leukemia were treated with the combination of MW and MTX, there was no improvement in survival compared with a group of animals treated with MTX alone; however, the group that received MTX before the MW exposure had a significantly reduced survival time compared with the group treated with MTX alone or with the group to which MTX was administered after MW.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Effect of short electromagnetic pulses on brain acetylcholine content and spontaneous motor activity of mice (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 89-92 
    Details
    ISSN: 0197-8462
    Keywords: microwave pulse ; motor activity ; brain acetylcholine ; 2,450 MHz ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Mice were exposed to a single 15-ms or 25-ms pulse of 2,450-MHz microwaves which increased brain temperature by 2 °C or 4 °C, respectively. Immediately after exposure, the mice became hypokinetic but began recovering within 5 minutes. The 25-ms pulse (18.7 j deposited in the brain) caused a significant decrease in acetylcholine content of the whole brain, probably owing to increased permeability of the membrane.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    In vitro microwave effects on human neutrophil precursor cells (CFU-C) (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 203-215 
    Details
    ISSN: 0197-8462
    Keywords: 2,450-MHz microwaves ; neutrophil ; colony-forming cells ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Human marrow cells were irradiated with 2450-MHz CW microwaves in a fluid-filled waveguide irradiation system. Cell exposure was conducted by placing a marrow cell suspension in 20-μl glass microcapillary tubes that were positioned in the exposure chamber, and irradiated at power densities from 31 to 1,000 mW/cm2 (with corresponding specific absorption rates of 62 to 2,000 mW/g) for 15 minutes. The temperature of the sample was maintained at a fixed point. Sham-irradiated (SI) and microwave-irradiated (MWI) cells were cultured in a methylcellulose culture system for neutrophil colony proliferation. There was no reduction in neutrophil colony number on days 6-7 or 12-14 in cells exposed at 31 or 62 mW/cm2, but as the power density was increased to 1,000 mW/cm2, there was a reduction in colony number of MWI cells compared with SI cells. The microwave interaction with the human neutrophil colony-forming cells was apparently not related to temperature rise, or to the state of cell cycle, and was irreversible.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Effect of nonionizing radiation on the purkinje cells of the uvula in squirrel monkey cerebellum (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 241-246 
    Details
    ISSN: 0197-8462
    Keywords: monkey cerebellum ; Purkinje cells ; nonionizing radiation ; microwaves ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Pregnant squirrel monkeys were exposed to 2450-MHz (CW) microwaves at an equivalent power density of 10 mW/cm2 (SAR 3.4 mW/g) for three hours daily in a cavity-cage module. The exposure began when pregnancy was determined by a hormonal method, and continued through the offspring's first 9.5 months. After irradiation, the brains of the offspring were fixed with formaldehyde, and the inferior vermis of each cerebella was removed and processed for histologic observations. Purkinje cell density in the uvula was determined in sagittal serial sections. There was no significant difference between control and experimental animals in the number of Purkinje cells per mm of Purkinje cell line (linear density), as well as in the density of Purkinje cells in the Purkinje cell layer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Biological effects of long-term exposure of rats to 970-MHz radiofrequency radiation (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 279-284 
    Details
    ISSN: 0197-8462
    Keywords: 970 MHz ; rats ; long-term exposure ; serum chemistry ; hematology ; lymphocytes ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Rats (N = 16) exposed individually in circularly polarized waveguides to 970-MHz electromagnetic radiation (SAR=2.5 mW/g, 22 h daily for 70 consecutive days) had significantly higher serum levels of triglycerides, albumin, and total protein compared with sham-irradiated controls. No difference was observed in the weights, hematologic profile, or in vitro lymphocyte responses to mitogens between these two groups. The higher serum levels of triglycerides in radiofrequency-radiation-exposed rats suggest a non-specific stress reaction.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Inhibition of growth rate of escherichia coli induced by extremely low-frequency weak magnetic fields (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 285-289 
    Details
    ISSN: 0197-8462
    Keywords: growth inhibition ; magnetic fields ; ELF ; Escherichia coli ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Cultures of Escherichia coli kept at 0 °C in a phosphate buffer solution were exposed to a sinusoidal weak 60- or 600-Hz magnetic field of strength 2 × 10-3 Tesla. A decrease of more than 40% in bacterial count was observed after a 60-h exposure to the magnetic field. Electron micrographs of exposed bacteria show ruptured cell walls, possibly due to the breaking away of flagella under the influence of the sinusoidally varying electromotive force.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020310
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Biological effects of a 765-kV transmission line: Exposures and thresholds in honeybee colonies (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 315-328 
    Details
    ISSN: 0197-8462
    Keywords: electric fields ; 60 Hz ; honeybees ; transmission lines ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Honeybee colonies exposed under a 765-kV, 60-Hz transmission line at 7 kV/m show the following sequence of effects: 1) increased motor activity with transient increase in hive temperature; 2) abnormal propolization; 3) impaired hive weight gain; 4) queen loss and abnormal production of queen cells; 5) decreased sealed brood; and 6) poor winter survival. When colonies were exposed at 5 different E fields (7, 5.5, 4.1, 1.8, and 0.65-0.85 kV/m) at incremental distances from the line, different thresholds for biologic effects were obtained. Hive net weights showed significant dose-related lags at the following exposures: 7 kV/m, one week; 5.5 kV/m, 2 weeks; and 4.1 kV/m, 11 weeks. The two lowest exposure groups had normal weight after 25 weeks. Abnormal propolization of hive entrances did not occur below 4.1 kV/m. Queen loss occurred in 6 of 7 colonies at 7 kV/m and 1 of 7 at 5.5 kV/m, but not below. Foraging rates were significantly lower only at 7 and 5.5 kV/m. Hive weight impairment and abnormal propolization occur at lower E-field intensity than other effects and limit the “biological effects corridor” of the transmission line to approximately 23 m beyond a ground line projection of each outer phase wire. Intrahive E fields of 15-100 kV/m were measured with a displacement current sensor. Step-potential-induced currents up to 0.5 μA were measured in an electrically equivalent bee model placed on the honeycomb in a hive exposed at 7 kV/m. At 1.8 kV/m body currents were a few nanoamperes, or two orders of magnitude lower, and these colonies showed no effects. E-field versus electric shock mechanisms are discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Alterations in the rat electrocardiogram induced by stationary magnetic fields (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 357-370 
    Details
    ISSN: 0197-8462
    Keywords: rat ; electrocardiogram ; stationary magnetic fields ; T-wave augmentation ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: A field strength dependent increase in the amplitude of the T-wave signal in the rat electrocardiogram (ECG) was observed during exposure to homogeneous, stationary magnetic fields. For 24 adult Sprague-Dawley and Buffalo rats of both sexes, the T-wave amplitude was found to increase by an average of 408% in a 2.0 Tesla (1 Tesla = 104 Gauss) field. No significant magnetically induced changes were observed in other components of the ECG record, including the P wave and the QRS complex. The minimum field level at which augmentation of the T wave could be detected was 0.3 Tesla. The magnetically induced increase in T-wave amplitude occurred instantaneously, and was immediately reversible after exposure to fields as high as 2.0 Tesla. No abnormalities in any component of the ECG record, including the T wave, were noted during a period of 3 weeks following cessation of a continuous 5-h exposure of rats to a 1.5-Tesla field. The heart rate and breathing rate of adult rats were not altered during, or subsequent to, application of fields up to 2.0 Tesla. The effect of animal orientation within the field was tested using juvenile rats 3-14 days old. The maximum increase in T-wave amplitude was observed when subjects were placed with the long axis of the body perpendicular to the lines of magnetic induction. These experimental observations, as well as theoretical considerations, suggest that augmentation of the signal amplitude in the T-wave segment of the ECG may result from a superimposed electrical potential generated by aortic blood flow in the presence of a stationary magnetic field.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Chronic exposure to 60-Hz electric fields: Effects on pineal function in the rat (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 371-380 
    Details
    ISSN: 0197-8462
    Keywords: electric fields ; 60 Hz ; pineal gland ; circadian rhythm ; melatonin ; 5 methoxytryptophol ; acetyl transferase ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: As a component of studies to search for effects of 60-Hz electric field exposure on mammalian endocrine function, concentrations of melatonin, 5-methoxytryptophol, and serotonin-Nacetyl transferase activity were measured in the pineal glands of rats exposed or sham-exposed at 65 kV/m for 30 days. In two replicate experiments there were statistically significant differences between exposed and control rats in that the normal nocturnal increase in pineal melatonin content was depressed in the exposed animals. Concentrations of 5-methoxytryptophol were increased in the pineal glands of the exposed groups when compared to shamexposed controls. An alteration was also observed in serotonin-N-acetyl transferase activity, with lower levels measured in pineal glands from exposed animals.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020408
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Power-frequency electric fields averaged over the body surfaces of grounded humans and animals (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 403-406 
    Details
    ISSN: 0197-8462
    Keywords: electric fields ; power-frequency ; 60 Hz ; dosimetry ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Calculated electric-field strengths averaged over the body surfaces of grounded humans, swine, rats, horses, and cattle exposed to vertical, uniform, power-frequency electric fields are presented. To produce the same average fields over the body surfaces of grounded animals, as that experienced by a grounded man exposed to an unperturbed vertical field of 10 kV/m, the following unperturbed fields are required: swine, 19 kV/m; rat, 37 kV/m; horse, 18 kV/m; cow, 18 kV/m.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020411
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Chronic exposure to a 60-Hz electric field: Effects on neuromuscular function in the rat (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 227-239 
    Details
    ISSN: 0197-8462
    Keywords: 60-Hz electric fields ; rats ; soleus muscle ; plantaris muscle ; neuromuscular function ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Neuromuscular function in adult male rats was studied following 30 days of exposure to a 60-Hz electric field at 100 kV/m (unperturbed field strength). Isometric force transducers were attached to the tendons of the plantaris (predominantly fast twitch), and soleus (predominantly slow twitch) muscles in the urethan-anesthetized rat. Square-wave stimuli were delivered to the distal stump of the transected sciatic nerve. Several measurements were used to characterize neuromuscular function, including twitch characteristics, chronaxie, tetanic and posttetanic potentiation, and fatigue and recovery. The results from three independent series of experiments are reported. Only recovery from fatigue in slow-twitch muscles was consistently and significantly affected (enhanced) by electrifield exposure. This effect does not appear to be mediated by field-induced changes in either neuromuscular transmission, or in the contractile mechanism itself. It is suggested that the effect may be mediated secondary to an effect on mechanisms regulating muscle blood flow or metabolism.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...