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  • 1
    Electronic Resource
    Electronic Resource
    Microscopy of the junctional region between human coronal primary and secondary dentine (1977)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 154 (1977), S. 133-145 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The junction between human primary dentine and regular and irregular secondary dentine was examined with a number of different light and electron microscopic techniques. In decalcified material, a narrow band along the innermost surface of the primary dentine stained intensely. The walls of the tubules within the band stained intensely, whereas the tubular walls within the bulk of the primary dentine were not stained. Generally, the walls of the tubules in both types of secondary dentine were also preferentially stained. Although not readily apparent in ground sections, observations of thin sections revealed a dramatic reduction in the number of tubules in regular secondary dentine. Generally, the radiodensity of the intertubular matrix was the same in primary and secondary dentine and the intensely stained band was not seen radiographically. The pulpal ends of the tubules in primary dentine were often occluded with a material having the same radiodensity as peritubular matrix. Both patent and occluded tubules were seen in irregular secondary dentine. Scanning electron microscopy of acid-etched specimens of secondary dentine revealed that some tubules had irregular walls of highly mineralized matrix which was less acid-soluble than the peritubular matrix of primary dentine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051540109
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  • 2
    Electronic Resource
    Electronic Resource
    Structure, histochemistry, ontogenetic development, and regeneration of the ocellus of Cladonema radiatum dujardin (cnidaria, hydrozoa, anthomedusae) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 313-331 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ectodermal eyes, 45-55 μm in diameter, of the cnidarian hydrozoan Cladonema radiatum Dujardin possess a lens approximately 15 μm in diameter enveloped by an eyecup (retina). An overlying layer of intensely vacuolated distal process of the adjoining epithelial cells forms a transparent cornea. The eyecup is composed of three cell types: basal cells, melanin-containing pigment cells, and photoreceptor cells. The last two cell types occur in the ratio of approximately 2:1. Histogenesis of the eye both during ontogeny and regeneration is described from light and electron microscopic investigations. During ontogeny the cell types forming the retina are derived from a compact group of morphologically undifferentiated cells, but during regeneration a primordium is formed by regeneration cells. In both cases the lens is built from distal nonnucleated cytoplasmic portions pinched off from the pigment cells. The cornea is formed by distal lamellar processes of the ocellus adjoining the epithelial cells. Through EM-histochemical methods (silver impregnation and DOPA-oxidase reaction) the pigment of the chromatophores of the retina was identified as melanin.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051670306
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  • 3
    Electronic Resource
    Electronic Resource
    The distribution of peritubular matrix in human coronal dentin (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 435-445 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Thin semi-serial ground sections of coronal dentin were examined radiographically. The bulk of the coronal dentin was characterized by the majority of the tubules having a distinct peritubular zone. With the exception of the tubules running from the tip of the cusp to the pulp cornu, the bulk of peritubular matrix forming the walls of the tubules was disposed eccentrically. The matrix was thicker on the cervical sides of the tubule than it was on the incisal sides. In a relatively narrow layer of the coronal dentin between the bulk of the dentin and the predentindentin border area the thickness of the peritubular matrix varied considerably. It was extremely narrow or absent in some tubules and reached its greatest thickness in others. The tubules in the predentin border area showed little or no evidence of peritubular matrix. The area of dentin beneath the central developmental groove differed somewhat from the bulk of the dentin. Many of the tubules at all levels of this area showed little radiographic evidence of peritubular matrix. Obliterated tubules were seen in some of the sections taken immediately above the predentin-dentin border area in the region of the pulp cornu and were always seen at the junction of the mantle dentin and the circumpulpal dentin beneath the central developmental groove.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051260405
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  • 4
    Electronic Resource
    Electronic Resource
    Sheath configurations in human cuspal enamel (1973)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 141 (1973), S. 479-489 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: To determine the prism sheath configurations in human cuspal enamel 80 teeth were initially ground to produce flat surfaces through the following planes: a horizontal series at successively greater distances from the dentinoenamel junction and longitudinally through the center of the cusps. Individual teeth were suspended in an acid-alcohol solution (1 cm3 conc. HCl in 100 cm3 95% ethanol) at 37°C for seven to ten days. The treatment “softened” the enamel to a depth of approximately 1 mm. The teeth were embedded in Epon and sectioned at 0.5 to 10 μm with a diamond knife. Thick and thin ground sections for phase contrast microscopy and acid-etched ground sections for Nomarski differential interference microscopy were prepared through the same regions. In thicker longitudinal sections, the prisms in gnarled enamel formed a zig-zag pattern which was unlike the twisting pattern generally observed in ground sections. The thinnest transverse sections showed the sheath outlines to be dramatically different from those seen elsewhere in the enamel. Some prism sheaths were circular, others were in the form of spirals. What could be described as sheaths within sheaths were also seen. In the thinnest longitudinal sections the prisms were seen to be elongated and discontinuous. Sheath outlines in enamel adjacent to the central core of gnarled enamel were similar to those described elsewhere in the body of the enamel. Keyhole, modified keyhole patterns and arcade forms were the dominant sheath patterns. Other atypical sheath configurations were seen scattered throughout this region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051410407
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  • 5
    Electronic Resource
    Electronic Resource
    Long-term analysis of organelle translocation in isolated axoplasm of Myxicola infundibulum (1988)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 10 (1988), S. 391-399 
    Details
    ISSN: 0886-1544
    Keywords: video microscopy ; axonal transport ; computer motion analysis ; giant axon ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Moving intra-axonal organelles demonstrate frequent variations in speed when viewed over several seconds. To evaluate these and other motion variations, a long-term analysis of organelle motion in isolated axoplasm of Myxicola infundibulum was carried out using differential interference contrast optics and analog and digital image enhancement techniques. Motion characteristics of individual organelles were analyzed for periods of up to 58 minutes. Three principle observations on organelle motion were made: (1) Classes of organelles of the same size demonstrated a 5- to 25-fold variation of speed, with the slowest speeds occurring most frequently; (2) organelle speeds over individual translocations (motion without stopping) are inversely proportional to their size, but the speeds calculated for the long-term analysis of organelle motion (total distance travelled/total observation time, including pauses) did not reflect this observation; and (3) organelles displayed variable trip lengths, durations, mean speeds, and pause durations, and the relationships between these variations showed no repetitive patterns. In contrast to reported observations of uniform velocities of organelles moving on isolated microtubule preparations, these observations suggest that a variety of factors must play a role in organelle translocation in Myxicola axoplasm.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970100306
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  • 6
    Electronic Resource
    Electronic Resource
    Solubilization, reconstitution, and attempted affinity chromatography of the sugar transporter of the erythrocyte membrane (1985)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 27 (1985), S. 83-96 
    Details
    ISSN: 0730-2312
    Keywords: human erythrocytes ; glucose transport ; membrane transport ; reconstitution ; membrane protein solubilization ; affinity chromatography ; phloretin derivatives ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Reconstitution of the sugar transport system of human erythrocytes into artificial liposomes was achieved by freezing, thawing, and sonicating preformed phospholipid vesicles in the presence of intact ghosts, protein-depleted ghosts, or detergent-treated ghosts. D-glucose equilibrium exchange activities and affinity constants in the range of the reported erythrocyte values were reached in the best experiments. Whereas the extraction of peripheral membrane proteins did not depress the transport function crucially after reconstituting these protein-depicted ghosts, the selective Solubilization of integral membrane proteins by a variety of nonionic detergents resulted in an uncontrollable, continuously increasing inactivation of the carrier. However, Emulphogene BC-720 extracts could be prepared in which the glucose transporter retained activity for days at 4°C. These extracts were applied to affinity chromatography matrices of phloretin-Agarose, prepared by coupling phloretinyl-3′-benzylamine (PBA) to CH-Sepharose 4B and to Affigel 202. Although the solubilized sugar transporter appeared to be selectively adsorbed to both PBA matrices, it could not be eluted by specific counter ligands or gentle eluants in a biologically active form. However, chaotropic agents could be used to elute intrinsic proteins, including bands 3 and 4. 5, from the Affigel affinity medium.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240270203
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  • 7
    Electronic Resource
    Electronic Resource
    Retransformation of a revertant cell line with the adenovirus E1 oncogenes and vanadate (1990)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 43 (1990), S. 293-296 
    Details
    ISSN: 0730-2312
    Keywords: phosphatase phosphotyrosine ; orthovanadate ; viral oncogenes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We have isolated a revertant cell line (G5) from an adenovirus transformed rat cell line (F4) which failed to express the integrated viral oncogenes. To determine whether the reversion mutation was acting in cis or trans the G5 cells were co-transfected with an E1 gene bearing expression plasmid and a neomycin photransferase bearing plasmid. 0418-resistant colonies were picked and shown to express the E1 proteins and to be tumorigenic. This re-transformation could be partially mimicked by treatment with vanadate, an inhibitor of phosphotyrosine phosphatases. These results show that the continued presence of the E1 proteins was required to maintain the transformed phenotype, and that the reversion mutation was a cis-acting event affecting directly the integrated E1 genes.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240430309
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  • 8
    Electronic Resource
    Electronic Resource
    Expression of heat shock genes during differentiation of mammalian osteoblasts and promyelocytic leukemia cells (1992)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 48 (1992), S. 277-287 
    Details
    ISSN: 0730-2312
    Keywords: HL-60 cells ; bone ; proliferation ; gene regulation ; hsp27 ; hsp60 ; hsp70 ; hsp89α ; hsp89β ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The progressive differentiation of both normal rat osteoblasts and HL-60 promyelocytic leukemia cells involves the sequential expression of specific genes encoding proteins that are characteristic of their respective developing cellular phenotypes. In addition to the selective expression of various phenotype marker genes, several members of the heat shock gene family exhibit differential expression throughout the developmental sequence of these two cell types. As determined by steady state mRNA levels, in both osteoblasts and HL-60 cells expression of hsp27, hsp60, hsp70, hsp89α, and hsp89β may be associated with the modifications in gene expression and cellular architecture that occur during differentiation.In both differentiation systems, the expression of hsp27 mRNA shows a 2.5-fold increase with the down-regulation of proliferation while hsp60 mRNA levels are maximal during active proliferation and subsequently decline post-proliferatively. mRNA expression of two members of the hsp90 family decreases with the shutdown of proliferation, with a parallel relationship between hsp89α mRNA levels and proliferation in osteoblasts and a delay in down-regulation of hsp89α mRNA levels in HL-60 cells and of hsp89β mRNA in both systems. Hsp70 mRNA rapidly increases, almost twofold, as proliferation decreases in HL-60 cells but during osteoblast growth and differentiation was only minimally detectable and showed no significant changes. Although the presence of the various hsp mRNA species is maintained at some level throughout the developmental sequence of both osteoblasts and HL-60 cells, changes in the extent to which the heat shock genes are expressed occur primarily in association with the decline of proliferative activity. The observed differences in patterns of expression for the various heat shock genes are consistent with involvement in mediating a series of regulatory events functionally related to the control of both cell growth and differentiation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240480308
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  • 9
    Electronic Resource
    Electronic Resource
    Regulation of the epidermal growth factor receptor by phosphorylation (1985)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 29 (1985), S. 195-208 
    Details
    ISSN: 0730-2312
    Keywords: epidermal growth factor receptor ; protein-tyrosine kinase ; self-phosphorylation ; protein kinase C ; oncogene ; growth factor ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The receptor for epidermal growth factor (EGF) is a glycosylated transmembrane phosphoprotein that exhibits EGF-stimulable protein tyrosine kinase activity. On EGF stimulation, the receptor undergoes a self-phosphorylation reaction at tyrosine residues located primarily in the extreme carboxyl-terminal region of the protein. Using enzymatically active EGF receptor purified by immunoaffinity chromatography from A431 human epidermoid carcinoma cells, the self-phosphorylation reaction has been characterized as a rapid, intramolecular process which is maximal at 30-37°C and exhibits a very low Km for ATP (0.2 μM). When phosphorylation of exogenous peptide substrates was measured as a function of receptor self-phosphorylation, tyrosine kinase activity was found to be enhanced two to threefold at 1-2 mol of phosphate per mol of receptor. Analysis of the dependence of the tyrosine kinase activity on ATP concentration yielded hyperbolic kinetics when plotted in double-reciprocal fashion, indicating that ATP can serve as an activator of the enzyme. Higher concentrations of peptide substrates were found to inhibit both the self- and peptide phosphorylation, but this inhibition could be overcome by first self-phosphorylating the enzyme. These results suggest that self-phosphorylation can remove a competitive/inhibitory constraint so that certain exogenous substrates can have greater access to the enzyme active site. In addition to self-phosphorylation, the EGF receptor can be phosphorylated on threonine residues by the calcium- and phospholipid-dependent protein kinase C. The sites on the EGF receptor phosphorylated in vitro by protein kinase C are identical to the sites phosphorylated on the receptor isolated from A431 cells exposed to the tumor promoters 12-O-tetradecanoylphorbol 13-acetate or teleocidin. This phosphorylation of the EGF receptor results in a suppression of its tyrosine kinase and EGF binding activities both in vivo and in vitro. The EGF receptor can thus be variably regulated by phosphorylation: self-phosphorylation can enhance tyrosine kinase activity whereas protein kinase C-catalyzed phosphorylation can depress enzyme activity. Because these two phosphorylations account for only a fraction of the phosphate present in the EGF receptor in vivo, other protein kinases can apparently phosphorylate the receptor and these may exert additional controls on EGF receptor/kinase function.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240290304
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  • 10
    Electronic Resource
    Electronic Resource
    Synaptic morphology of substance P terminals on catecholamine neurons in the commissural subnucleus of the nucleus tractus solitarii in the rat (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 29 (1994), S. 177-183 
    Details
    ISSN: 1059-910X
    Keywords: Sinus afferent pathway ; SP interneurons ; Double immunocytochemistry ; Ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The ultrastructure of substance P-containing nerve terminals synapsing on catecholamine neurons in the rat commissural subnucleus of the nucleus tractus solitarii (NTScom) was studied using a double immunocytochemical labeling technique. Although there were numerous tyrosine hydroxylase-immunoreactive (TH-I) somata present, substance P immunoreactive (SP-I) cell bodies were only occasionally found in the NTScom. At the light microscopic level, many SP-I terminals were seen closely associated with TH-I dendrites and somata. At the electron microscopic level, SP-I terminals synapsing on TH-I structures were also readily encountered. SP-I terminals contained small, clear, and predominantly spherical vesicles (32 ± 4 nm diameter), as well as large dense-cored vesicles approximately 100 nm in diameter. Postsynaptic TH-I dendritic profiles of various calibers and somata were encountered. These postsynaptic TH-I structures often showed postsynaptic densities. The morphological features of the SP-TH synapses in the present study, that is, the size of synaptic vesicles and the presence of postsynaptic densities, are quite different from those of central carotid sinus afferent synapses reported in our previous study [Chen et al. (1992), J. Neurocytol., 21:137-147]. Therefore, most of the SP terminals of the SP-TH synapses in the NTScom appear not to originate from the carotid sinus afferents. SP-I second-order neurons of the carotid sinus afferent pathway [Chen et al. (1991), J. Auton. Nerv. Syst., 33:97-98] may be one of the possible sources of such terminals. © 1994 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070290216
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