GLORIA

GEOMAR Library Ocean Research Information Access

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
  • 1
    Electronic Resource
    Electronic Resource
    Aspects of shell formation in eggs of the tuatara, Sphenodon punctatus (1988)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 197 (1988), S. 147-157 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The flexible shell from eggs of the tuatara (Sphenodon punctatus) is comprised of both calcareous and fibrous components. The calcareous material is organized into columns that extend deep into the fibrous shell membrane. Many of the fibers of the membrane are enclosed within the crystalline matrix of the columns. Columns widen and flatten slightly at the outer surface of the eggshell to form cap-like structures composed of a compact crystalline matrix containing no fibers. The outer surface of eggs laid prior to completion of shell formation consists of a series of nodes obscured by a densely fibrous matrix. Similar nodes also are found at the inner surface of partially shelled eggs. The nodes represent the outer and inner aspects of columns that had not completed formation prior to oviposition. Our interpretation is that a layer (or layers) of the shell membrane forms first, with nucleation of columns occurring shortly thereafter. Columns grow into the membrane a short distance and enclose fibers of the membrane, but the primary direction of column growth is toward what will become the outer aspect of the shell. Calcareous columns and the shell membrane form more or less in concert until crystal growth outstrips that of the membrane and a cap-like apex of compact crystalline material is formed. The end result is an eggshell in which the shell membrane and calcareous material form a single unit for much of the thickness of the shell.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051970203
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Regulation of cell motility, morphology, and growth by sulfated glycosaminoglycans (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 273-281 
    Details
    ISSN: 0886-1544
    Keywords: heparin ; glycosaminoglycans ; fibronectin ; cell growth factors ; cell migration ; cell adhesion ; cell morphology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Due to the recent observation that heparin binds to several growth factors and cell adhesion molecules, the effect of heparin on biological processes governed by growth factors and cell adhesion molecules was investigated. Pharmacological doses of heparin were found to alter cell growth rate, cellular morphology, and cell motility.Concentrations (μg/ml) of heparin or dextran sulfate decreased cell growth rate, but not the final cell density attained in plateau phase. The effect of heparin on cell growth rate was most pronounced when cells were cultured in low concentrations of serum. A heparin-induced decrease in cell growth rate could be reversed by addition of platelet-derived growth factor (PDGF), a heparin-binding growth factor.Heparin altered the morphology of all cell lines studied to various degrees. The effect of heparin on cell morphology was quantitated by measuring the heparin-induced change in cell surface area. HT-1080 and HeLa cells nearly doubled in surface area upon exposure to 10μg/ml heparin. Since several heparin-binding cell adhesion proteins mediate both cell spreading and cell migration, the influence of heparin on cell migration was investigated with an improved version of the phagokinetic track technique. Low concentrations of heparin and dextran sulfate were found to increase the rate of cell migration in a dose-dependent fashion.Since the quantitative effect of heparin on cell growth rate, morphology, and migration depends on the cell line studied, it is suggested that three separate phenomena may be involved. The results presented indicate a central role for sulfated glycosaminoglycans in the control of both cell growth and cell-cell interactions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060304
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Three microtubule-organizing centers are required for ascus growth and sporulation in the fungus Sordaria macrospora (1992)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 22 (1992), S. 257-273 
    Details
    ISSN: 0886-1544
    Keywords: fungal cytoskeleton ; microtubules ; nocodazole ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The microtubule system of the Sordaria macrospora ascus was examined by antitubulin immunofluorescence, without the removal of the cell wall. The complex cytoskeleton revealed three possible microtubule-organizing centers (MTOCs): the spindle pole body (SPB), the nuclear envelope, and an apical organizing center. MPM-2, a mitotic phosphoprotein antibody which reacts with MTOCs, stained the apical center in a developmentally specific manner, and the nuclear envelope and SPB in a cell cycle-dependent fashion. Nocodazole was used in both high (10-15 μg/ml) and low (0.5 μg/ml) concentrations to depolymerize the networks and reveal their points of origin and recovery. The apical center was active from prophase I to the end of first meiosis. The nuclear envelope was the site of microtubule nucleation in early prophase and at the telophase/interphase transition, while SPBs were active in both nuclear division and sporulation.Mutant strains deficient in sporulation and with aberrant morphology were analyzed by antitubulin and MPM-2 immunofluorescence. Shape mutants showed abnormal or absent apical organizing centers and abnormal cortical microtubule patterns, indicating a possible role for the cortical network in the establishment and maintenance of ascus shape. © 1992 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970220406
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Thrombin, epidermal growth factor, and phorbol myristate acetate stimulate tubulin polymerization in quiescent cells: A potential link to mitogenesis (1992)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 23 (1992), S. 265-278 
    Details
    ISSN: 0886-1544
    Keywords: growth factors ; phorbol 12-myristate 13-acetate ; microtubule-tubulin equilibrium ; initiation of DNA synthesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Previous studies suggest that alterations in the microtubule (MT)-tubulin equilibrium during G0/G1 affect mitogenesis. To determine the effect of growth factors on the MT-tubulin equilibrium, we developed a radioactive monoclonal antibody binding assay (Ball et al.: J. Cell. Biol. 103:1033-1041, 1986). With this assay, 3H-Ab 1 - 1.1 binding to cytoskeletons in confluent populations of cultured cells is proportional to the number of tubulin subunits polymerized into MTs. We now show that purified α-thrombin increases 3H-Ab 1 - 1.1 binding to cytoskeletons of serum-arrested mouse embryo (ME) fibroblasts from 1.5- to 3-fold. This stimulation is dose-dependent and correlates with concentrations of thrombin required for initiation of DNA synthesis. Other mitogenic factors, epidermal growth factor (EGF) and phorbol 12-myristate 13-acetate (PMA), also stimulate MT polymerization. Addition of colchicine (0.3 μM) eight hours after growth factor addition blocks stimulation of 3H-thymidine incorporation by thrombin, EGF, or PMA, suggesting that tubulin polymerization or subsequent events triggered by MT polymerization are required for cells to enter a proliferative cycle. Consistent with models for autoregulation of tubulin synthesis, thrombin, EGF, and PMA all increase tubulin synthesis 9 to 15 hr after growth factor addition, raising the possibility that the decrease in free tubulin and subsequent stimulation of tubulin synthesis is linked to progression of cells into a proliferative cycle. Colchicine addition to these cells also stimulates DNA synthesis, but colchicine-stimulated cells enter S phase 6 to 8 hr later than those stimulated by growth factors. This delayed stimulation may be related to the time required for degradation of tubulin- colchicine complexes below a critical level. These data suggest that regulation of cell proliferation may be linked to increased MT polymerization and the resulting decrease in free tubulin pools. © 1992 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970230406
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Fura 2 analysis of cytosolic calcium regulation in elutriated rat gastric parietal cells (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 139 (1989), S. 632-640 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The calcium probe, Fura 2, is used to establish and partially characterize histamine-, carbachol- and forskolin-induced calcium transients in enriched parietal cell populations prepared by centrifugal elutriation of dispersed rat fundic mucosa cell isolates. The magnitude of the maximal carbachol response, which is blocked by atropine but not cimetidine, is nearly five times that of histamine or forskolin. Time to peak responses for carbachol, forskolin, and histamine are approximately 7, 17, and 28 sec, respectively. Carbachol-, histamine-, and forskolin-induced increases in Fura 2 fluorescence appear dependent upon extracellular calcium, since these responses are attentuated in low calcium media and blocked by EGTA in low-calcium media or by lanthanum in high- or low-calcium medium. Trifluoperazine and fenoctimine, at concentrations that inhibit secretion, have no effect on either carbachol- or histamine-induced increases in cytosolic calcium. Seven major calcium/EGTA-sensitive phosphopro-teins are identified by SDS-PAGE electrophoresis of ATP 32P-labeled cell sonicates. We conclude that cytosolic calcium in enriched rat gastric parietal cell populations is regulated by secretagogue receptor-controlled calcium channels. We postulate that these channels may be controlled by cyclic AMP-dependent phosphorylation, since neither changes in cyclic AMP nor calcium alone mediate the effects of secretagogues entirely, but the interplay between these two second-messenger systems potentiates the actions of these agents. The role of cytosolic calcium as a second messenger in secretagogue action appears similar to that of cyclic AMP in that a specific cellular concentration must be reached to initiate acid secretion.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041390325
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Invasive activity and chemotactic response to growth factors by Kaposi's sarcoma cells (1988)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 36 (1988), S. 369-376 
    Details
    ISSN: 0730-2312
    Keywords: Kaposi's sarcoma ; chemotaxis ; invasion ; growth factors ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Kaposi's sarcoma (KS) is a relatively low grade neoplasm, classically occurring in the skin of elderly men. A more virulent and invasive form of Kaposi's sarcoma has been described in patients with acquired immune deficiency syndrome (AIDS). The origin and identification of the tumor cells in these lesions is controversial. Here we have studied the behavior of cells derived from KS lesions in an in vitro assay which measures the ability of cells to invade through a reconstituted basement membrane. In agreement with previous work, KS cells obtained under selective culture conditions were invasive showing activity comparable to that of malignant tumor cells. Normal fibroblasts, smooth muscle cells, and endothelial cells did not demonstrate invasive behavior under the same experimental conditions. To characterize further the nature of the KS cells we tested the chemotactic response of cells from the most invasive line to a variety of growth factors and compared their response to those of fibroblasts, smooth muscle, and endothelial cells. These studies suggest that normal cells respond to a unique repertoire of chemotactic factors. The chemotactic response of the KS cells most closely resembled that of smooth muscle cells and was quite distinct from endothelial cells. These results indicate that the KS-derived cultures contain invasive cells with a smooth muscle cell-like phenotype.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240360406
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Epidermal growth factor stimulates phosphatidylinositol turnover in human foreskin fibroblasts without activation of protein kinase C (1989)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 41 (1989), S. 201-205 
    Details
    ISSN: 0730-2312
    Keywords: EGF ; cell proliferation ; tyrosine kinase ; second messenger ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Epidermal growth factor stimulates phosphatidylinositol turnover in human foreskin fibroblasts. This is a primary cell culture with normal numbers of epidermal growth factor receptors that is stimulated to divide by epidermal growth factor. Increases are seen in the inositol phospholipids and inositol phosphates. Despite this activation of phosphatidylinositol turnover, there is no detectable activation of protein kinase C.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240410405
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Morphogenesis of human cardiac outflow (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 213 (1985), S. 578-586 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The developmental anatomy of human cardiac outflow was studied in a series of 16 normal embryos (gestational days 29-39, crown-rump length 6-20 mm, stages 14-19). Structural features and kinetics during truncal septation (TS) were described from external photographs, serial histological sections, and computer graphic reconstructions of selected tissues.Early in the period studied, the tubular myocardium ensheathed the single cardiac lumen and spiralling conotruncal ridges, which were filled with mesenchymal cells during days 31-33. As TS began (late stage 16), the aorticopulmonary (AP) septum appeared across the dorsal wall of the aortic sac between arches IV and VI. Mesenchymal condensations formed within the AP septum, crossing the lumen bifurcation to extend along the truncal ridges to the myocardium. During days 35-37, the cephalic margin of the myocardium grew or folded in toward these mesenchymal condensations between the developing valves and within the nearby conal ridges, which appeared to fuse to separate the subvalvular outflow channels by day 39.These observations are consistent with studies in chicks and rats which suggest that mesenchymal condensations or cell death foci interact with the distal myocardial rim during TS to form a structural septation complex dividing the two arterial streams.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092130414
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Patterns of skeletal histologic change through time: Comparison of an archaic native american population with modern populations (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 226 (1990), S. 307-313 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: This paper compares patterns of histologic change in an archaic Native American population with those in modern white populations. Histologic sections were removed from core biopsies taken from the anterior femoral cortex of an archeologic sample of Pecos Indians. The data demonstrate many microstructural similarities between the Pecos and modern populations, even though they were genetically and culturally distinct. Pecos women had small Haversian canals and large osteon mean wall thickness, with no clear evidence of an intracortical bone volume deficit even in the older age groups, although significant marrow cavity expansion occurred in both males and females with age. No striking relationships were found between bone tissue changes and gross geometric changes with age. The data suggest that a more active life-style is associated with greater osteon mean wall thickness or osteon population density, but that it alone does not protect against significant bone loss on the cortical-endosteal surface.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092260306
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Morphogenesis of the truncus arteriosus of the chick embryo heart: Movements of autoradiographic tattoos during septation (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 218 (1987), S. 434-440 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: In order to trace tissue movements during septation of the embryonic truncus arteriosus into aortic and pulmonary cardiac outlets, the cephalic margin of the developing tubular heart of chick embryos was tattooed at Hamilton-Hamburger Stages 20-22 using diffusion micropipettes filled with 0.5% agarose and radioactive macromolecular precursors (tritiated thymidine, uridine, and leucine). Following further incubation for 2, 48, or 96 hours, the locations of such tatoos were determined by autoradiography of sectioned tissue and computer reconstruction of the developing outflow tract.Two hours after tattooing, radiolabeled cells were clustered at the right distal margin of the myocardial tube, as intended. Two days later, during septation of the outflow tract into the two arterial streams, label was concentrated along the posterior margin of the myocardium, between the developing aortic and pulmonary valve anlagen to the embryo's right and left, respectively. Four days following tattooing, as truncal septation neared completion, remaining label was found primarily to the left of the aortic valve ring posterior to the pulmonary outlet. The movements of thymidine tattoos during septation were demonstrated in a series of 31 embryos, 14 fixed at 2 hours, 12 at 2 days, and 5 at 4 days following tattooing; similar results were seen in uridine and leucine labeled hearts.The motion of such tattoos in the developing chick heart suggests that the left side of the definitive semilunar valve ring derives from the right distal margin of the primitive tubular heart and that normal morphogenesis of the great arterial streams involves both retraction and rotation of the embryonic truncus arteriosus.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092180411
    Location Call Number Limitation 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...