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  • Life and Medical Sciences  (11)
  • 2005-2009
  • 1990-1994  (7)
  • 1975-1979  (2)
  • 1930-1934  (1)
  • 1920-1924  (1)
  • 1
    Electronic Resource
    Electronic Resource
    The cytology of several species of iceryine coccids, with special reference to parthenogenesis and haploidy (1930)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 50 (1930), S. 475-495 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Four species of iceryine coccids have been studied cytologically in connection with certain breeding experiments. These are Icerya littoralis, Icerya montserratensis, Echinicerya anomola, and Crypticerya rosae. For the three first-named species the complete chromosomal history has been established, and the evidence on the fourth, Crypticerya rosae, is sufficient to indicate that it differs in no essential respect from the others. The following résumé may, therefore, be considered to apply to all four species. The females are diploid, with a chromosome number of four, and the males are haploid, with a chromosome number of two. Oogenesis proceeds quite normally; two tetrads are formed and two maturation divisions occur in which the chromosomes are reduced to two in each female pronucleus. All eggs undergo this reduction: if the eggs are then fertilized, the diploid number is thus restored and development into females ensues; if the eggs remain unfertilized, whether in the body of a virgin or of a fertilized female, they develop parthenogenetically, with no restoration of diploidy, into haploid males. The spermatogenesis of the haploid males involves a single meiotic division, demonstrably equational in character; the accompanying cytoplasmic division is suppressed, and from each of the binucleate spermatids thus produced two spermatozoa are formed. These conditions are contrasted with the functional hermaphroditism and haploid parthenogenesis of Icerya purchasi.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050500208
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  • 2
    Electronic Resource
    Electronic Resource
    Fine structure of the gills of some Indian air-breathing fishes (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979), S. 169-193 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A detailed account is given of the structure of the gills of Clarias batrachus, Heteropneustes (= Saccobranchus) fossilis, Channa punctata, Monopterus (= Amphipnous) cuchia and Boleophthalmus boddaerti, based upon light and electron microscopy. In all five species the basic organization into primary and secondary lamellae is apparent but the latter are very much more modified in Monopterus.Three main layers separate the water and blood on the surface of the secondary lamellae. The outer epithelium is usually two layered but may be multilayered close to the origin of the secondary lamellae from the gill filament. The basement membrane is relatively thin and a middle dense layer containing collagen fibrils separates two clear layers. The pillar cells, so characteristic of secondary lamellae, are present in all except Monopterus and flanges from these cells surround the blood channels with the exception of the marginal channels. The latter are lined by endothelial cells which line all the blood channels of Monopterus.The overall thickness of the three layers comprising the water/blood barrier ranges from 1.5 to 13 microns. A number of modifications to this basic organization can be related to the degree of dependence of the different species on air-breathing.Boleophthalmus is the only species commonly found in brackish water and its secondary lamellae have well developed lymphoid spaces between two layers of the epithelium. Special densely-stained regions of the pillar cell flanges were also present in this fish and may have a supporting function.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051600205
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  • 3
    Electronic Resource
    Electronic Resource
    Growth and protein phosphorylation in the Nb2 lymphoma: Effect of prolactin, cAMP, and agents that activate adenylate cyclase (1990)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 43 (1990), S. 327-337 
    Details
    ISSN: 0730-2312
    Keywords: forskolin ; cholera toxin ; pertussis toxin ; interleukin-2 ; T lymphocyte ; G protein ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The Nb2 T lymphoma is unique in that these lymphocytes proliferate in response to prolactin as well as in response to interleukin-2. In this study, we have examined the responsiveness of the adenylate cyclase system in Nb2 cells and the role of this signaling system in regulating proliferation and protein phosphorylation. An analog of cAMP inhibited prolactin-stimulated proliferation and blocked a prolactin-induced decrease in protein phosphorylation. Forskolin, a potent activator of adenylate cyclase in T lymphocytes, did not elevate cAMP levels in Nb2 cells and was not an effective inhibitor of prolactin-induced proliferation. In fact, one preparation of forskolin stimulated proliferation of quiescent Nb2 cells. Like forskolin, prostaglandin E2 did not stimulate cAMP production in Nb2 cells even though, it increased cAMP in a preparation of rat peripheral blood lymphocytes. Cholera toxin appeared to ADP-ribosylate a stimulatory guanine nucleotide-binding protein in Nb2 cells, but the toxin did not increase intracellular levels of cAMP nor was it a potent anti-mitogenic agent. Pertussis toxin, an agent that can increase cAMP production through suppression of the inhibitory guanine nucleotide-binding protein, exerted only minor anti-proliferative actions on prolactin-stimulated Nb2 cells. These data suggest that cAMP inhibits Nb2 cell proliferation and prolactin-induced changes in protein phosphorylation but that the adenylate cyclase system in our clone of Nb2 cells responds poorly to agents that normally increase cAMP.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240430405
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  • 4
    Electronic Resource
    Electronic Resource
    Cell cycle arrest by prostaglandin A1 at the G1/S phase interface with up-regulation of oncogenes in S-49 cyc- cells (1994)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 265-272 
    Details
    ISSN: 0730-2312
    Keywords: DNA synthesis ; cAMP ; cell growth inhibition ; lymphoma ; PGA1 ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Our previous studies have implied that prostaglandins inhibit cell growth independent of cAMP. Recent reports, however, have suggested that prostaglandin arrest of the cell cycle may be mediated through protein kinase A. In this report, in order to eliminate the role of c-AMP in prostaglandin mediated cell cycle arrest, we use the-49 lymphoma variant (cyc-) cells that lack adenylate cyclase activity. We demonstrate that dimethyl prostaglandin A1 (dmPGA1) inhibits DNA synthesis and cell growth in cyc- cells. DNA synthesis is inhibited 42% by dmPGA1 (50 μM) despite the fact that this cell line lacks cellular components needed for cAMP generation. The ability to decrease DNA synthesis depends upon the specific prostaglandin structure with the most effective form possessing the α,β unsaturated ketone ring. Dimethyl PGA1 is most effective in inhibiting DNA synthesis in cyc- cells, with prostaglandins PGE1 and PGB1 being less potent inhibitors of DNA synthesis. DmPGE2 caused a significant stimulation of DNA synthesis. S-49 cyc- variant cells exposed to (30-50 μm) dmPGA1, arrested in the G1 phase of the cell cycle within 24 h. This growth arrest was reversed when the prostaglandin was removed from the cultured cells; growth resumed within hours showing that this treatment is not toxic. The S-49 cyc- cells were chosen not only for their lack of adenylate cyclase activity, but also because their cell cycle has been extensively studied and time requirements for G1, S, G2, and M phases are known. Within hours after prostaglandin removal the cells resume active DNA synthesis, and cell number doubles within 15 h suggesting rapid entry into S-phase DNA synthesis from the G1 cell cycle block. The S-49 cyc- cells are known to have a G1/S boundary through M phase transition time of 14.8 h, making the location of the prostaglandin cell cycle arrest at or very near the G1/S interface. The oncogenes, c-fos and c-myc which are normally expressed during G1 in proliferating cells have a 2-3 fold enhanced expression in prostaglandin G1 arrested cells. These data using the S-49 variants demonstrate that dmPGA1 inhibits DNA synthesis and arrests the cell cycle independent of cAMP-mediated effects. The prostaglandin arrested cells maintain the gene expression of a G1 synchronous cell which suggests a unique molecular mechanism for prostaglandin action in arresting cell growth. These properties indicate that this compound may be an effective tool to study molecular mechanisms of regulation of the cell cycle.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240540302
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  • 5
    Electronic Resource
    Electronic Resource
    Reproduction in Acroschismus wheeleri Pierce (1924)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 39 (1924), S. 157-205 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050390106
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  • 6
    Electronic Resource
    Electronic Resource
    Structure of the respiratory islets of accessory respiratory organs and their relationship with the gills in the climbing perch, Anabas testudineus (Teleostei, Perciformes) (1991)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 209 (1991), S. 241-256 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The epithelial and sub-epithelial organization of the accessory respiratory organs of Anabas testudineus has been compared with that of gills by using light and transmission electron microscopy. The details of vascular supply of respiratory islets (RI) and gill filaments and the presence of venous sinusoids in the two systems suggest that the RI have been derived from gill filaments and lamellae. The biserial arrangement of transverse capillaries (TC) in the respiratory islets (RI) is evident under the scanning electron microscope and their homology with the gill filaments and their secondary lamellae has been established. The two sets of transverse capillaries of respiratory islets have been derived either from embryonic transverse or marginal channels of two sets of lamellae of a gill filament. These capillaries with their endothelial septate valves and tongue-like processes offer resistance to blood flow.Gill filaments have two vascular pathways, arterio-arterial and arterio-venous. However, the RI of accessory respiratory organs contain the arterio-venous pathways. This arrangement as well as the septate transverse capillaries may lower the “pulmonary” blood pressure considerably.Two types of mitochondria-rich cells are identified: i) chloride cells with flat microvilli bearing surfaces, devoid of apical pit and (ii) an elongated cell type with sac-like endoplasmic reticulum, with apical pit that comes into close contact with the complex matrix of macrophages, lymphocytes and other loose cells of the epithelium. These cells may be associated with detoxification of the internal media of fish inhabiting foul waters.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052090302
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  • 7
    Electronic Resource
    Electronic Resource
    Immunological characterization of hypoxanthine-guanine phosphoribosyl transferase mutants of mouse L cells: Evidence for mutations at different loci in the HGPRT gene (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 85 (1975), S. 307-320 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A large collection (105) of mouse L cell mutants lacking hypoxanthine-guanine phosphoribosyl transferase activity (HGPRT; E. C. 2.4.2.8) were analyzed for the presence of serologically cross reacting material (CRM). Antibody directed against highly purified mouse liver HGPRT was used for detecting CRM activity by two methods: (1) the standard precipitation-inhibition assay; and (2) a radioimmune-precipitation assay. The latter assay proved to have far greater sensitivity for the detection of altered forms of HGPRT. Approximately 40% of the HGPRT- cell lines contain CRM activity (i.e., were CRM+). This indicates that a minimum of 40% of the HGPRT- clones arose as a result of mutations in the HGPRT structural gene. The CRM+ cell lines were shown to contain different levels of CRM activity. Measurements of the heat sensitivity of CRM in the different HGPRT- cell lines showed a broad spectrum of CRM heat inactivation kinetics. These latter two observations provide strong evidence that the mutations giving rise to the HGPRT-CRM+ phenotype occurred at different sites in the HGPRT structural gene.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040850217
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  • 8
    Electronic Resource
    Electronic Resource
    E.coli hemolysin interactions with prokaryotic and eukaryotic cell membranes (1992)
    New York, NY : Wiley-Blackwell
    BioEssays 14 (1992), S. 519-525 
    Details
    ISSN: 0265-9247
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The hemolysin toxin (HlyA) is secreted across both the cytoplasmic and outer membranes of pathogenic Escherichia coli and forms membrane pores in cells of the host immune system, causing cell dysfunction and death. The processes underlying the interaction of HlyA with the bacterial and mammalian cell membranes are remarkable. Secretion of HlyA occurs without a periplasmic intermediate and is directed by an uncleaved C-terminal targetting signal and the HlyB and HlyD translocator proteins, the former being a member of a transporter superfamily central to import and export of a wide range of substrates by prokaryotic and eukaryotic cells. The separate process by which HlyA is targetted to mammalian cell membranes is dependent upon fatty acylation of a non-toxic precursor, proHlyA. This is achieved by a novel mechanism directed by the activator protein HlyC, which binds to an internal proHlyA recognition sequence and provides specificity for the transfer of fatty acid from cellular acyl carrier protein.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bies.950140804
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  • 9
    Electronic Resource
    Electronic Resource
    Bindings of the lectins Griffonia simplicifolia-1 and pokeweed mitogen mark discrete stages of myoepithelial-like differentiation of cell lines from the rat mammary gland (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 146 (1991), S. 222-233 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Individual single-cell-cloned cell lines of the different rat mammary (Rama) cell types have been tested for their ability to bind the lectins Griffonia simplicifolia-1(GS-1) and pokeweed mitogen (PWM) using fluorescent, histochemical, and radioactive assays. Myoepithelial-like cell lines isolated from neonatal rat mammary glands and from nonmetastasizing tumors strongly bind GS-1 and PWM, whereas the corresponding epithelial and fibroblastic cell lines do not. When the epithelial cell lines are grown on floating gels of polymerised rat tail collagen, the basally situated or peripheral cells are stained strongly with peroxidase-conjugated lectins, whereas the apically or luminally situated cells are unstained. The capacity of cell lines intermediate in morphology between epithelial and myoepithelial-like cells to bind to GS-1 is as follows: Rama 25 epithelial 〈 Rama 25-12 〈 Rama 25-I1 〈 Rama 25-14 〈 Rama 29 myoepithelial-like cells, the same order as for other markers of myoepithelial cells. Conjugated PWM, however, binds only to the myoepithelial-like cell lines. Treatment of Rama 25 epithelial cells with agents that disrupt microtubules accelerates their conversion to elongated, myoepithelial-like cells in culture. The binding of cells to GS-1 is observed prior to, and that to PWM after, the major morphological change. It is suggested that the stepwise appearances of carbohydrate receptors for GS-1 and PWM mark discrete stages in the differentiation of epithelial to myoepithelial-like cells in culture, in the same way that they mark similar differentiation stages in ductal development in mammary glands of prepubertal rats.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041460206
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  • 10
    Electronic Resource
    Electronic Resource
    Fibroblasts inhibit mineralised bone nodule formation by rat bone marrow stromal cells in vitro (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 146 (1991), S. 442-450 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ability of rat skin fibroblasts (RSF) and human periodontal ligament fibroblasts (HPL) to inhibit the formation of mineralised bone nodules in rat bone marrow stromal cell (BMSC) cultures was studied. Co-culture of HPL or RSF with BMSC resulted in a large reduction of bone nodule formation when compared with controls. Conditioned medium from HPL or RSF cultures inhibited bone nodule formation in a dose-dependent manner. HPL-conditioned medium depressed cell proliferation and alkaline phosphatase expression in BMSC cultures. These effects were not due to increased cytotoxicity or nutrient depletion. Inhibitory activity was recovered in a fraction of less than 1 kD following ultrafiltration and was insensitive to freeze-thawing. The inhibitory activity was blocked when HPL cultures were grown in the presence of 105M indomethacin. Dose-dependent inhibition of bone nodule formation was also observed in cultures incubated with prostaglandins E2 (at 10-6M) or F2α(at 10-7). The results indicate that fibroblasts may inhibit osteoblast differentiation and function in part by release of soluble factors including prostaglandins.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041460315
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