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  • 1
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 207 (1983), S. 665-671 
    ISSN: 0003-276X
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: A microcomputer-based facility is described that permits the data required for three-dimensional reconstructions to be collected quickly and inexpensively from serial sections. The facility consists of a microcomputer, a digitizer tablet, a graphics terminal, a printer, a plotter, and telephone coupler. Images of serial sections are superimposed on the digitizer tablet. Contours of interest on each section are digitized and the coordinates are stored on “floppy” disks. The problems of putting successive sections in correct register and of taking into account magnification factors are discussed briefly. Use of the facility for high-resolution applications is also considered.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 29 (1994), S. 20-28 
    ISSN: 0886-1544
    Schlagwort(e): proliferation ; large T antigen ; peripheral nervous system ; cytoskeleton ; microtubules ; myelination ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Schwann cells (SC), the myelinating cells of the peripheral nervous system, show a remarkable capacity to switch from a differentiated state to a proliferative state both during development and peripheral nerve regeneration. In order to better understand the regulatory mechanisms involved with this change we are studying a Schwann cell line transfected with the SV-40 large T gene (TSC). Serum-free medium combined with elevating intra-cellular cAMP levels produced a slower proliferating TSC whose morphology changed from pleiomorphic to process bearing, reminiscent of primary SC in culture. This change was abrogated by colcemid but was unaltered by cytochalasin D, indicating a major role for microtubules. Ultrastructural studies demonstrated numerous microtubules in the cellular extensions which correlated with strong immunocytochemical staining for tubulin in the processes. Analysis of cytoskeletal fractions from the treated cells revealed a greater proportion of tubulin in the polymerized state compared with untreated cells which closely resembled the distribution in primary SC. The cytoskeletal changes observed in the TSC as a result of elevating the intra-cellular cAMP levels may reflect the earliest cellular changes in the induction of myelination. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 10 (1988), S. 18-27 
    ISSN: 0886-1544
    Schlagwort(e): chromosome structure ; spatial organization ; optical sectioning ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Fluorescence microscopy, uniquely, provides the ability to examine specific components within intact, even living, cells. Unfortunately, high-resolution conventional fluorescence microscopy is intrinsically a two-dimensional technique and performs poorly with specimens thicker than about 0.5 μm. Probing the spatial organization of components within cells has required the development of new methods optimized for three-dimensional data collection, processing, display, and interpretation. Our interest in understanding the relationship between chromosome structure and function has led us to develop the necessary methodology for exploring cell structures in three dimensions. It is now possible to determine directly the three-dimensional spatial organization of diploid chromosomes within intact nuclei throughout most of the mitotic the cell cycle.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    ISSN: 0897-3806
    Schlagwort(e): computer-assisted instruction ; computer graphics ; gross ; anatomy ; thorax ; Life and Medical Sciences ; Miscellaneous Medical
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: We describe a three-dimensional computer-generated model of the human mediastinum. Contours were manually traced from photographs of a serially sectioned, unfixed frozen cadaver block, Using software developed in-house, the contours were digitized, automatically assembled and placed in registration, and displayed on a high performance graphics workstation as surfaced images. The model thus produced has advantages over traditional representations of anatomical structures; it is realistic, accurate, efficient, and flexible. Each anatomical component of the mediastinum is stored as a separate file in the computer and can be selectively accessed, displayed, and manipulated, allowing the model to be disassembled, reassembled, dissected, and viewed in any orientation. The model can be divided into a series of transversely cut “slabs,” the surfaces of which correlated with the anatomy displayed in the original cryosections and with radiological scans, thus permitting 2-D sectional anatomy to be viewed in the context of the 3-D model. Animation of the model can be accomplished by recording pre-planned scripts onto videodiscs. The videodiscs serve as image archives that can be viewed in an interactive, self-paced manner or accessed from a computer-based multimedia system that is being developed by the Digital Anatomist Program. Anatomical reconstructions based on datasets of x-, y-, z-coordinates have potential clinical applications as models that can be displayed to match the sectional planes of radiological images. The mediastinum model we describe is part of a large image database being developed by the Digital Anatomist Program that will form the spatial component of a knowledge base in structural biology. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 36 (1993), S. 164-173 
    ISSN: 1040-452X
    Schlagwort(e): Basic proteins ; Semenogelin processing ; Sperm head ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: A basic protein with a relative molecular mass of 19 kDa has been identified and isolated to purity from sonication-resistant, partially demembranized human sperm nuclei. Several criteria prove that this is the unique sperm-specific protein, which was previously thought to be a sperm/testis histone. Partial primary structure sequencing demonstrates homologies with human seminal α-inhibins and semenogelin. From the sequence and Western-blotting data with antibodies against basic seminal inhibin-like peptide, we propose that this 19-kD protein is a product of 52-kDa semenogelin processing. The 19-kDa protein was not found among seminal plasma proteins and may be protected from further cleavage into inhibin-like peptides by its association with the sperm head Immunofluorescence data indicate its localization in the nuclear periphery, with preferential concentration at the acrosome calyx boundary. © 1993 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 24 (1993), S. 142-156 
    ISSN: 1059-910X
    Schlagwort(e): Sensory processing ; Olfactory coding ; Olfaction ; Odor stimulation ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Complete understanding of the role of the mammalian main olfactory bulb in sensory processing has remained elusive despite many detailed studies on its anatomy and physiology. Several lines of recent evidence viewed in the context of earlier knowledge have provided new insights into the bulbar mechanisms of olfactory coding. The output cells of the olfactory bulb receive a localized olfactory nerve input and interneuronal input via dendrodendritic synapses on distinct sets of dendrites. The spatial arrangement of granule cell contacts on output cell basal dendrites suggests that lateral inhibitory interactions may occur between neighboring output cells. The input from olfactory receptor cell axons to the bulb also has spatial order, but does not represent a precise map of the receptor surface. Recent studies with antibodies and lectins suggest that different groups of axons from chemically similar receptor cells collect into certain glomeruli, even if the axons originate from cells that are not contiguous in the mucosa. Electrophysiological studies have begun to explore the participation of spatially organized circuits in olfactory processing. The degree to which neighboring output cells respond similarly to odor stimulation, for example, depends on the distance between the cells, with those further apart showing complementary responses. Also, a single output cell can show 2 or more different temporal response patterns when different odors are presented. Intracellular recordings indicate that these responses are shaped by IPSPs. Electrical stimulation during such recordings shows that some mitral cells are excited by nerve inputs close to their glomerular tufts, while they are inhibited by nerve inputs to other parts of the bulb. Finally, recordings from granule and periglomerular cells indicate their potential in mediating components of output cell odor responses. These considerations suggest that the olfactory bulb performs a spatially based analysis on the information coming from the receptor cells. While the spatial organization of the olfactory bulb is probably not faithfully represented in the projections to the olfactory cortex, bulbocortical projections are not random. The fact that spatial factors exist at each of these levels in the olfactory system must be considered in developing models of central olfactory processing. © 1993 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 29 (1994), S. 310-318 
    ISSN: 1059-910X
    Schlagwort(e): Hippocampus ; Dendrites ; 3-D imaging ; Pyramidal cell ; Neurophysiology ; Confocal microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Studies were undertaken to develop microscopic methods and imaging procedures that would permit identification of sites of intradendritic microelectrode recordings from pyramidal cells in hippocampal slice preparations. Intradendritic recording were obtained with sharp microelectrodes filled with the dye lucifer yellow. Following a recording session a neuron was iontophoretically injected with the dye and imaged by fluorescence videomicroscopy. Images were stored on videotape for later analysis. They provided a record of the location of the microelectrode recording site. After withdrawal of the microelectrode, slices were processed histologically and imaged a second time with a Bio-Rad 600 confocal attachment on an Olympus BH-2 microscope. Confocal images provided detailed anatomical information in three dimensions. In most instances, a clear identification of the recording site was achieved by comparing video images containing the recording electrode and confocal images.Neurophysiological recordings obtained from proximal and distal apical dendrites were markedly different. Proximal dendritic recordings were similar to those obtained from pyramidal cell soma. However, distal dendrites were not electroresponsive when depolarized by intracellular current injection. The techniques described here, or variations that employ patch electrodes, could provide valuable information that should further an understanding of the properties of dendrites in the central nervous system. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 141-148 
    ISSN: 1040-452X
    Schlagwort(e): Embryos ; Autoradiography ; Radiolabeled nucleic acids ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Two methods for preparing embryos for autoradiographic study of newly synthesized nucleic acids are described and compared. The first method consists of rapidly fixing radiolabeled embryos with acetic acid:methanol, spreading them on glass slides and exposing them for 8 days with a photographic emulsion. The second method consists of fixing, embedding in resin, and sectioning the embryos before their exposure with the emulsion for 3 weeks. Both techniques have many applications in studies of early embryonic activity, but the spread technique is very sensitive, simpler, and faster. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 13 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 25 (1990), S. 177-185 
    ISSN: 1040-452X
    Schlagwort(e): Ovoperoxidase ; Exocytosis ; Extracellular macromolecular assembly ; Anions ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Eggs of the sea urchin Strongylocentrotus purpuratus were fertilized in normal and in several chloride-deficient sea waters ([CI-]: normal 〉 isethionate 〉 methyl sulfonate 〉 bromide). The fertilization envelopes (FE) were thinner and failed to harden, and the characteristic I-T transition did not occur. The permeability of the experimental FEs, as determined by release of protein from the perivitelline space, increased in the order of decreasing [CI-]. Release of the enzymes β-1, 3-glucanase and cortical granule protease were not significantly altered. On the other hand, release of ovoperoxidase was increased three to four times in bromide sea water. Furthermore, a dose-response was observed in varying concentrations of bromide-normal sea water. With decreasing chloride (increasing bromide) concentration, more ovoperoxidase activity was observed. Cytochemical localization of ovoperoxidase activity with diaminobenzidine revealed almost a total lack of staining of FEs from bromide-substituted sea water. The results suggest that in chloride-deficient sea waters protein incorporation into the nascent FE is impaired. At least in the case of bromide, the incorporation of ovoperoxidase into the nascent FE was also inhibited.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 128 (1969), S. 113-130 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: A principal component analysis revealed that the two major components of mandibular shape variation among individuals within breeding groups of white-tailed deer in Canada and the United States involve contrasts between the mandible and the dentition and between the premolars and the molars. Size variation appeared to account for 34% of the total variation within the groups, and the two major shape variations accounted for 23% and 8% respectively.A canonical analysis was used to identify the major components of mandibular variation among the breeding groups and to provide measures of the proportion of the total variation accounted for by each component. Among male groups, size variation was associated with latitude, and the major shape variation was closely associated with longitude, so a bivariate plot of the first two canonical variates reflected the general geographic orientation of the populations.The mandibular size in a Tennessee population that descended from Wisconsin and Michigan ancestors appears to have not decreased appreciably in the more southerly habitat after introduction more than 20 years ago. Changes in range conditions in eastern Upper Michigan over the past 30 years have not influenced local mandibular morphology as reflected by the first two canonical variates. Regardless of general smallness of individuals, the mandibular morphology of the deer from the Cross Timbers area in Kansas appears to approximate more closely that of northern populations than that of the more southerly populations from Oklahoma and Texas.Sexual dimorphism on the first two canonical axes was observed.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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