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  • Articles  (172)
  • Life and Medical Sciences  (172)
  • Inorganic Chemistry
  • 1995-1999
  • 1990-1994  (172)
  • 1910-1914
  • 1992  (172)
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  • Natural Sciences in General  (172)
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  • Articles  (172)
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  • 1995-1999
  • 1990-1994  (172)
  • 1910-1914
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  • 101
    Electronic Resource
    Electronic Resource
    Fine structural aspects of secretion and extrinsic innervation in the olfactory mucosa (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 111-127 
    Details
    ISSN: 1059-910X
    Keywords: Bowman's glands ; Sustentacular cells ; Goblet cells ; Nerve terminalsa ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The mucus at the surface of the olfactory mucosa constitutes the milieu in which perireceptor events associated with olfactory transduction occur. In this review, the ultrastructure of olfactory mucus and of the secretory cells that synthesize and secrete olfactory mucus in the vertebrate olfactory mucosa is described. Bowman's glands are present in the olfactory mucosa of all vertebrates except fish. They consist of acini, which may contain mucous or serous cells or both, and ducts that traverse the olfactory epithelium to deliver secretions to the epithelial surface. Sustentacular cells are present in the olfactory epithelium of all vertebrates. In fish, amphibia, reptiles, and birds, they are secretory; in mammals, they generally are considered to be “nonsecretory,” although they may participate in the regulation of the mucous composition through micropinocytotic secretion and uptake. Goblet cells occur in the olfactory epithelium of fish and secrete a mucous product.Secretion from Bowman's glands and vasomotor activity in the olfactory mucosa are regulated by neural elements extrinsic to the primary olfactory neurons. Nerve fibers described in early anatomical studies and characterized by immunohistochemical studies contain a variety of neuroactive peptides and have several targets within the olfactory mucosa. Ultrastructural studies of nerve terminals in the olfactory mucosa have demonstrated the presence of adrenergic, cholinergic and peptidergic input to glands, blood vessels, and melanocytes in the lamina propria and of peptidergic terminals in the olfactory epithelium. The neural origins of the extrinsic nerve fibers and terminals are the trigeminal, terminal, and autonomic systems. © 1992 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230203
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  • 102
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    Reflection electron microscopy and interferometry of atomic steps on gold and platinum single crystal surfaces (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 450-456 
    Details
    ISSN: 1059-910X
    Keywords: Holography ; Interferometrical and holographical experiments ; Phase shifts ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Two beam interferences produced using an electrostatic biprism, which is inserted in the position of the selected area diaphragm of a commercial electron microscope, may be used in reflection electron microscopy to determine the phase shifts induced by structures on single crystal surfaces. A description of our interferometrical and holographical experiments on the phase shift at steps on (111)Au and (111)Pt single crystal surfaces is given and a straight forward interpretation of the results in terms of refraction will be discussed. As a particular result phase shifts of π and 0.9π were measured for monatomic steps on (111)gold and (111)platinum surfaces, respectively.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200414
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  • 103
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    Localization of adenovirus DNA by in situ hybridization electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 23-31 
    Details
    ISSN: 1059-910X
    Keywords: Autoradiography ; Nick translation ; Nuclear matrix ; Biotination ; DNA replication ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Biotinylated deoxyadenosine triphosphate (dATP) (Bio-7-dATP) and 3H deoxythymidine triphosphate (dTTP) labeled adenovirus DNA were hybridized in situ to thin sections of Lowicryl K4M-embedded and whole-mount extracted HeLa cells infected with adenovirus. The biotinylated probe was detected by exposing the extracted cells or sections to antibodies against biotin followed by colloidal gold-conjugated secondary antibodies and then critical-point dried while 3H-dTTP labeled probe by electron microscopic autoradiography. On Lowicryl K4M sections, gold particles and silver grains were mainly restricted in the nucleus. Furthermore, whole-mount results suggested that replicating adenovirus DNA is localized on the nuclear matrix of its host cell. In this paper, the described non-radioactive procedures for hybrid detection offered several advantages: (a) rapid signal detection; (ob) superior morphological preservation and spatial resolution; (c) precise localization; and (d) on Lowicryl K4M sections, signal to noise equivalent to radiolabeling.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210104
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  • 104
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    Unified approach for computing interplanar spacing and location of projection of HOLZ reflection onto the ZOLZ (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 51-52 
    Details
    ISSN: 1059-910X
    Keywords: CBED ; HOLZ ; Material science ; Reciprocal lattice ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210107
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  • 105
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    Morphofunctional aspects of the mammalian pineal gland (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 136-157 
    Details
    ISSN: 1059-910X
    Keywords: Pinealocytes ; Ultrastructure ; Secretion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The primary aim of this review is to present the current state of knowledge of the ultrastructure of the mammalian pineal gland, with emphasis on its functional aspects. Basic ultrastructural features of the mammalian pinealocytes are presented with special attention paid to ultrastructural aspects of pineal secretion.
    Additional Material: 38 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210206
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  • 106
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    Ultrastructure of the mammalian pinealocyte under natural and experimental conditions: Quantitative aspects (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 116-123 
    Details
    ISSN: 1059-910X
    Keywords: Quantitative morphology ; Morphometry ; Synaptic ribbons ; Dense-cored vesicles ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: This review briefly summarizes data accumulated on the quantitative aspects of the ultrastructure of the mammalian pinealocyte. Quantitative changes have been demonstrated under natural and experimental conditions in pinealocyte cell organelles in various species. Special attention is paid to two cytoplasmic components most frequently studied by means of quantitative electron microscopy, namely, dense-core vesicles and “synaptic” ribbons.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/jemt.1070210204
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  • 107
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    Endocytic pathways in the olfactory and vomeronasal epithelia of the mouse: Ultrastructure and uptake of tracers (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 128-141 
    Details
    ISSN: 1059-910X
    Keywords: Olfactory epithelium ; Vomeronasal epithelium ; Endocytosis ; Ultrastructure ; Olfactory pigment ; Mouse ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Mammalian olfactory neurons possess a well-developed system of endocytic vesicles, endosomes, and lysosomes in their dendrites and perikarya. Vomeronasal neurons are similar and also contain much perikaryal agranular endoplasmic reticulum (AER). Olfactory supporting cells contain endocytic vesicles and endosomes associated closely with abundant fenestrated AER, and vesicles and numerous large dense vacuoles are present basally. Vomeronasal supporting cells have little AER, and few dense vacuoles occur in their bases. In olfactory neurons, ultrastructural tracers (0.08% horseradish peroxidase, thorium dioxide, ferritin) are endocytosed by olfactory receptor endings and transported to the cell body, where their movement is halted in lysosomes. Higher concentrations (1%) of horseradish peroxidase penetrate olfactory receptor plasma membranes and intercellular junctions. In olfactory supporting cells, endocytosed tracers pass through endosomes to accumulate in dense basal vacuoles. These observations indicate that olfactory sensory membranes are rapidly cycled and that endocytosed materials are trapped within the epithelium. It is proposed that in the olfactory epithelium, endocytosis presents redundant odorants to the enzymes of the supporting cell AER to prevent their accumulation, whereas in the vomeronasal epithelium the receptor cells carry out this activity. © 1992 Wiley-Liss, Inc.
    Additional Material: 29 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230204
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  • 108
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    Ultrastructural studies of microtubules and microtubule organizing centers of the vertebrate olfactory neuron (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 142-156 
    Details
    ISSN: 1059-910X
    Keywords: Cytoskeleton ; Ultrastructure ; Microtubules ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The olfactory neuron is specialized along its length into highly determined morphological regions. These regions include the dendritic cilia, dendritic vesicle, dendritic shaft proper, perikaryon, axon, zone of transition where the axon widens as it approaches its termination, and the axon terminal. Except for the zone of transition and the terminal, characteristic populations of microtubules occur in these compartments. In the olfactory vesicle, three discrete microtubule organizing centers (MTOCs) nucleate microtubules: the basal body, the lateral foot associated with the body, and dense masses of nearby material. Little is known about MTOCs elsewhere in the neuron, although the polarity of the axonal microtubules indicate that they originate at or near the perikaryon. An attempt is made to summarize what is known of the origin, structure, distribution, and function of microtubules in vertebrate olfactory neurons, which are useful model systems in which to study microtubules. Information about olfactory neuron microtubules may be applicable to neurons in general (e.g., the discovery that axons contain microtubules of uniform polarity was first made in the olfactory neuron) or to microtubules in other eukaryotic cells. © 1992 Wiley-Liss, Inc.
    Additional Material: 19 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230205
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  • 109
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    Computer simulation of electron microscope diffraction and images, edited by W. Krakow and M. O'Keefe. The Minerals, Metals, and Materials Society, Warrendale, Pennsylvania, 1989, 275 pp, $50.00 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 200-200 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
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    URL: http://dx.doi.org/10.1002/jemt.1070230209
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  • 110
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    Growth of olfactory epithelial tissue in vitro: Lectin staining of axons (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 173-180 
    Details
    ISSN: 1059-910X
    Keywords: Organ culture ; Glycoconjugate ; Concanavalin A ; Wheat germ agglutinin ; Soybean agglutinin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In vitro methods have been used to study several aspects of development of olfactory epithelium. In this paper, the value of growing olfactory tissue in explant cultures is reviewed and some experiments are reported on the identification of lectin receptors on olfactory axons by the use of lectin-gold complexes. Both concanavalin A-gold (con A-gold) and wheat germ agglutinin-gold consistently decorated olfactory axons in explant cultures. Con A-gold also bound to the tips of growth cone filopodia, suggesting the glycoconjugate molecules containing α-methyl-pyranoside are important in adherence of growth cones to their substrate. The wide range in density of lectin-gold particles suggested that axons, and the sensory cells from which they arise, are not a uniform population, i.e., they have different molecular fingerprints. This was supported by the observation that soybean agglutinin-gold stained some axons very well, but others remained unstained. Peanut agglutinin did not bind to any axons. © 1992 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230207
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  • 111
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    Immunocytochemical localization of cell adhesion molecules in the developing and mature olfactory system (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 157-172 
    Details
    ISSN: 1059-910X
    Keywords: N-CAM ; L1 ; AMOG ; J1 ; L2-HNK-1 ; Olfactory system ; Development ; Immunocytochemistry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The localization of Ca++-independent cell adhesion molecules (CAMS) in the developing and mature olfactory epithelium and bulb is reviewed. The CAMs included in this article are the neural cell adhesion molecule (N-CAM), the 180 kD component of N-CAM (N-CAM 180), the embryonic form of N-CAM (E-N-CAM), L1 glycoproteins, J1 glycoproteins, and the adhesion molecule on glia (AMOG). In addition, the expression of the L2-HNK-1 carbohydrate epitope, shared by N-CAM, L1, J1 and myelin-associated glycoprotein (MAG) in the adult olfactory epithelium and bulb has also been documented. For the localization of these molecules at the light and electron microscopic levels, immunocytochemical techniques were used and are described in detail.During development and organogenesis, the olfactory system exhibits a pattern of CAM expression similar to the general pattern described for the developing nervous system. In the adult olfactory system, however, a significant retention of CAMs characteristic for developmental and morphogenetic processes, such as E-N-CAM, AMOG, as well as the high molecular weight components of J1 glycoproteins, can be observed. The retention of these embryonic features are most likely associated with the cell turnover and high plasticity of this system. Moreover, the predominance of N-CAM 180 with respect to other components of N-CAM, as well as the absence of the L2/HNK-1 carbohydrate epitope, are also particular traits of the primary olfactory system which could be associated with its exceptional properties. © 1992 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/jemt.1070230206
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  • 112
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    Lectins bind differentially to cilia and microvilli of major and minor cell populations in olfactory and nasal respiratory epithelia (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 181-199 
    Details
    ISSN: 1059-910X
    Keywords: Olfactory receptor cells ; Olfactory supporting cells ; Microvillous cells ; Olfactory signal-transduction ; Freeze-etching ; Freeze-substitution ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Binding of colloidal gold-conjugated lectins was studied in cilia and microvilli of rat olfactory and respiratory epithelia. This was done in sections of rapidly frozen, freeze-substituted specimens embedded in Lowicryl K11M or, for wheat germ agglutinin (WGA) alone, in deep-etched replicas. Olfactory dendritic endings and cilia labeled with WGA and faintly with soybean agglutinin (SBA); olfactory supporting cell microvilli bound only Dolichos biflorus agglutinin (DBA). Microvilli of an infrequent cell bound peanut agglutinin (PNA), SBA, and WGA. These microvilli labeled more strongly with the last two lectins than the olfactory cilia. Respiratory cilia bound WGA and, somewhat more weakly, PNA; microvilli of ciliated respiratory cells bound all four lectins. Visualization of specific labeling improved after preincubation of sections with neuraminidase, except for DBA where lectin binding was abolished. PNA labeling was seen only after neuraminidase preincubation. The densities of membrane surface particles that labeled with WGA corresponded with those of fracture plane particles in a quantitative freeze-fracture, deepetch analysis. Therefore, a considerable fraction of the WGA-bound particles could reflect transmembrane proteins in olfactory dendritic endings and cilia and in respiratory cilia. The possible nature of these particles is discussed. © 1992 Wiley-Liss, Inc.
    Additional Material: 24 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230208
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  • 113
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    Masthead (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992) 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070230301
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  • 114
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    Structures of grain boundaries in long-chain te crystals observed by high-resolution transmission electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 207-218 
    Details
    ISSN: 1059-910X
    Keywords: HRTEM ; Te ; Grain boundary ; Vacuum-deposited film ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Vacuum-deposited Te crystals, composed of endless chains of the right-handed or left-handed spiral, have been investigated by high-resolution electron microscopy with the aid of image simulation. A (010) grain boundary, which accompanies edge dislocations having an extra layer of the width of one Te chain, has been observed. A through-focal series of images reveal that it is not a reflectional nor a rotational twin boundary but a small angle grain boundary in a single crystal or an inversion twin. The lattice on one side of the boundary is shifted from that on the other side by [001]c/3 + [120]a/8, and inclined at 1.1° around the c-axis of the other side. Also found between crystallites of [100] and [011] orientation is a grain boundary which is built with the (011) facets on one side of the boundary and the (211) or (0,1,10) facets on another side. © 1992 Wiley-Liss, Inc.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230303
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  • 115
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    Comparison of bromine and permanganate as ultrastructural stains for lignin in plants infected by the fungus Colletotrichum lagenarium (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 201-206 
    Details
    ISSN: 1059-910X
    Keywords: Energy dispersive X-ray microanalysis ; Appressoria ; Lignin localization ; Histochemistry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Transmission electron microscopy (TEM) and energy dispersive X-ray microanalysis (EDS) were used to localize manganese from KMnO4, and bromine, as ultrastructural stains for lignin in an herbaceous plant. The Spookie cultivar of pumpkin is susceptible to infection by the fungus Colletotrichum lagenarium and served as a model system to compare the Br and KMnO4 techniques. Bromine was used in a fixation/staining procedure, and in separate experiments, KMnO4 was used as either a fixative or as a postsection stain. The technique for using bromine was modified from the woody plant procedure by adding a paraformaldehyde prefixation step. With the bromine procedure, cell walls were well-preserved, but the cytoplasm was heavily extracted. The KMnO4 procedures produced well-fixed cytoplasm, but with some staining artifacts. With all procedures, EDS dot mapping demonstrated lignin deposition in the cell walls specifically associated with sites of fungal infection. Lignin was also localized in secondary walls of tracheary elements, sites known to be highly lignified. The bromine procedure provided the most specific localization of lignin with a minimum of artifact. The specific applications of these stains provided data on the ultrastructural localization of lignin which contributed to the elucidation of its role in the interactions between pathogenic fungi in both their resistant and susceptible plant hosts. © 1992 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/jemt.1070230302
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  • 116
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    Limitations of monastral blue as a vascular label: Rapid rate of clearance is age-dependent, and interactions with anesthetics depress arterial blood pressure in rats (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 219-224 
    Details
    ISSN: 1059-910X
    Keywords: Inflammation ; Venule ; Evans blue ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Monastral blue (MB) has been described as an inexpensive, nontoxic vascular label. Discrepancies as to its rate of removal from circulation and physiological side effects prompted this study in which retention time of MB in the vascular system and effects of MB upon arterial blood pressure with different anesthetics (halothane, isoflurane, and pentobarbital) were measured in rats. Arterial pressure was monitored during intravenous infusion of MB with or without Evans blue, an albumin label. Localized areas of leakage were created by injecting 30 μL of 10-4 M histamine into abdominal dermis at -2, 0, 5, 7, 10, and 15 minutes from infusion of MB. Mean arterial pressure decreased by 25-30% after MB infusion when halothane or isoflurane was used, but not with pentobarbital. Sites which leaked at 10 and 15 minutes did not usefully label with MB, although Evans blue-labelled albumin appeared in the interstitium. Younger, lighter rats (125-200 vs. 200-250 gm) retained MB longer in circulation, and had a shorter duration of MB-induced hypotension. Spectrophotometric analysis of rat serum showed rapid elimination of MB from the vascular system, with a half-life of 3.5 ± 1.9 minutes. While MB remains a useful vascular label, its rapid removal from the circulation and its hypotensive effect must be recognized. © 1992 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/jemt.1070230304
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  • 117
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    A technique for exposure of the glycoproteic matrix (zona pellucida and mucus) for scanning electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 225-229 
    Details
    ISSN: 1059-910X
    Keywords: Scanning electron microscopy ; Ultrastructure ; Zona pellucida ; Mucus ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The fine structure of the zona pellucida (ZP) covering the oocyte and of the mucus covering the surface of the intestinal villi was investigated by using a new method employing ruthenium red (RR), saponin, and osmium-thiocarbohydrazide impregnation.The glycoproteic matrices both appeared constituted by thin filaments (ranging from 22 to 50 nm in thickness) anastomosed to form a very fine network.RR prevented the dissolution and/or alteration of glycoproteins and polyanionic carbohydrates induced by acqueous fixatives. Saponin was a detergent of the soluble proteins. Osmium-thiocarbohydrazide preserved the glycoproteic matrix filaments from the mechanical stress induced by dehydration and critical point drying and reduced filaments packing and shrinkage. The technical improvement was demonstrated by the following results: 1) a regular arrangement of the filaments network; 2) a thickness of mucus filaments smaller than that obtained with other methods of preparation; 3) a homogeneous thickness of ZP filaments.This method allowed a very detailed study of the fine structural organization of the ZP and intestinal mucus. Therefore, this technique can be useful for a better evaluation of the morphodynamic of these and other glycoproteic matrices. © 1992 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/jemt.1070230305
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  • 118
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    Improved method for the preparation of TiN-coated WC-Co-based samples for cross-sectional AEM investigation (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 239-242 
    Details
    ISSN: 1059-910X
    Keywords: Braze alloys ; WC ; XTEM sample preparation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: An improved method for the preparation of cross-sectional thin foils of coated WC-Co samples for studies by analytical electron microscopy is described. A braze alloy is used to join the sections of the sample together and the resulting sample is stable during subsequent grinding, dimpling, and milling operations. Cross-sectional micrographs provide examples of the efficacy of this method. No microstructural alteration associated with the brazing operation was observed. © 1992 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/jemt.1070230307
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  • 119
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    Effect of crystal and beam tilt on simulated high-resolution TEM images of interfaces (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 230-238 
    Details
    ISSN: 1059-910X
    Keywords: High-resolution electron microscopy ; Twin boundaries ; Interphase boundaries ; Compositional order ; Reflex images ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The effects of crystal and beam tilt on high-resolution transmission electron microscope (HRTEM) images of planar coherent interfaces were investigated by multislice image simulations. It was found that a beam tilt of 0.5 Bragg angle (θB) was sufficient to introduce detrimental artifacts into most images of interfaces in crystals only 1/8ξ000 thick, while crystal tilt had a much smaller effect even for crystals 1ξ000 thick. Effects produced in HRTEM images of interfaces by crystal and beam tilt included the introduction of additional periodicities and loss of compositional detail across a boundary, translation of a boundary from its actual position, and apparent mismatch of atomic planes across a perfectly coherent interface. These results indicate that alignment of the electron beam parallel to the optic axis is critical for reliable HRTEM imaging of interfaces in materials. Techniques for obtaining accurate alignment are also discussed. © 1992 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/jemt.1070230306
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    Accurate d-spacings from zero-order laue zone patterns (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 243-247 
    Details
    ISSN: 1059-910X
    Keywords: Electron diffraction ; d-spacings ; Least-squares ; ZOLZ patterns ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Experimental d-spacing values are criteria towards the identification of crystallites by electron diffraction. Conclusive identifications often rely on accurate d-spacings. It is shown here that accurate orthogonal components (in mm) for the primitive unit vectors of a zero-level diffraction pattern can be obtained through least-squares processing of (x,y) coordinates for all spots on the film. Valid vectors hom the origin spot to any spot in the plane of the film are integer linear combinations of the two selected unit vectors. Accurate lengths and standard deviations for such vectors therefore can be calculated from the least-squares results. Corresponding d-spacings can then be calculated from the vector lengths on the film and the camera constant. In order to obtain d-spacing values that are not only precise, but also accurate, an accurate value of the camera constant should be used. This requires calibration of the experimental setup with reference materials in the same experimental conditions, with careful control of the sample height. For the same quality of measurements, the improvement in the accuracy of the d-spacings obtained with the proposed method is approximately proportional to the square root of the number of measurements taken. Practically, typical improvement in accuracy is about threefold, and accuracies of a fraction of a percent in d-spacings are achievable in this way. The above approach has been programmed as an option in the NRCBED program. © 1992 Wiley-Liss, Inc.
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    Preparation of cross-section specimens for transmission electron microscopy from α-Al2O3/Ni solid state bonded bicrystal interfaces (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 248-251 
    Details
    ISSN: 1059-910X
    Keywords: TEM cross-section specimens ; Alumina-nickel bicrystals ; Metal-ceramic solid state bonded interfaces ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The technique which is described combines the advantages of the techniques formerly proposed in the literature in each stage of the preparation of transmission electron microscopy (TEM) specimens including a single metal-ceramic interface. It allows easy handling of the thin foils in spite of their brittleness. Preferential thinning of the softer material in the two-phase foil is prevented, and both sides of the interface are thinned down to comparable thicknesses. The nickel-alumina bicrystal interface observed in TEM is neat and free from any reaction layer. This method is easily adaptable to other metal-ceramic systems. © 1992 Wiley-Liss, Inc.
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    Scanning electron microscopy of rat tail tendon collagen (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 260-261 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230311
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    InP sample preparation for the TEM by photochemical etching, ion milling, and chemical thinning (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 252-259 
    Details
    ISSN: 1059-910X
    Keywords: Semiconductor ; Plan view ; Microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Photochemical etching (PCE) as a method for preparation of InP semiconductor plan view samples for the transmission electron microscope is demonstrated and compared to the methods of ion milling and chemical thinning. PCE can produce small area samples for TEM analysis quickly and accurately. Also, the resulting thin regions are surrounded by a built-in stabilizing structure that improves handleability and reduces the occurrence of handling induced fracture. © 1992 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
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    Masthead (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992) 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070230401
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    Introduction (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 263-263 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070230402
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    Dynamics of golgi impregnation in neurons (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 264-274 
    Details
    ISSN: 1059-910X
    Keywords: CNS ; Light microscopy ; Electron microscopy ; Cerebral cortex ; Nerve cell ; Impregnation method ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: This paper describes the early stages of impregnation by the Golgi rapid method in sections and blocks of brain tissue. Aldehyde-fixed and potassium dichromate-treated sections of cerebral cortex were placed on glass slides and coverslipped. The dichromate solution was then replaced by a silver nitrate solution, and events taking place in the section were monitored and time-lapse recorded until the impregnation was interrupted and the sections subsequently prepared for electron microscopy. The tissue blocks, fixed and chromated in the same way, were placed into a silver nitrate solution for 30 min to 24 h and the progress of impregnation compared with the results obtained in the sections on the glass slides.Two basic modes of impregnation were observed, apparently in direct relation to the process of crystallization of silver chromate: crystals of silver chromate growing directly from the surface of the tissue into the nerve cell via its transected plasma membranes, and microcrystalline precipitate of silver chromate spreading into the nerve cell from nucleation centres dispersed in the tissue. The precipitate grows inside the cell as in a preformed channel until the cell has been filled. If the nucleation begins extracellularly, the precipitate extends into the narrow intercellular gaps. Electron microscopy showed that the crystalline precipitate consisted of multilamellar formations containing dense coalesced granules that did not cross plasma or endocellular membrane boundaries. © 1992 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/jemt.1070230403
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    Techniques for converting golgi precipitate in CNS neurons into stable electron microscopic markers (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 275-288 
    Details
    ISSN: 1059-910X
    Keywords: Golgi-electron microscopy ; Gold substitution ; Chemical reduction ; Stabilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Direct electron microscopy of nervous tissue stained with the Golgi impregnation method is unsatisfactory because the cytoplasm of the cell bodies and processes of the impregnated neurons are completely filled with a compact precipitate of electron dense silver chromate. This precipitate entirely obscures the cytological details of the impregnated neurons. Because of its solidity and instability in aqueous solutions, the silver chromate is also a source of inconvenience during the preparation of the ultrathin sections.This review summarizes methods that have been developed with the aim of replacing the Golgi precipitate in CNS neurons with a more convenient electron dense material - for example, heavy metal salts or metallic particles. Conversion of the precipitate into a stable electron dense marker is done before the material is embedded for electron microscopy. The methods include lead, gold, and bromide substitution, treatment with ammonia, direct chemical reduction into metallic silver, and photoreduction of the silver chromate into silver through irradiation with ultraviolet light. © 1992 Wiley-Liss, Inc.
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    Application of the Golgi/electron microscopy technique for cell identification in immunocytochemical, retrograde labeling, and developmental studies of hippocampal neurons (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 306-323 
    Details
    ISSN: 1059-910X
    Keywords: Section Golgi impregnation ; Cholinergic synapses ; Neuronal specificity ; Neural transplantation ; Slice culture ; Neuronal plasticity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In this study the Golgi/electron microscopy (EM) technique has been used for an analysis of the fine structure, specific synaptic connections, and differentiation of neurons in the hippocampus and fascia dentata of rodents. In a first series of experiments the specific synaptic contacts formed between cholinergic terminals and identified hippocampal neurons were studied. By means of a variant of the section Golgi impregnation procedure, Vibratome sections immunostained for choline acetyltransferase, the acetylcholine-synthesizing enzyme, were Golgi-impregnated in order to identify the target neurons of cholinergic terminals in the hippocampus. It could be shown with this combined approach that cholinergic septohippocampal fibers form a variety of synapses with different target structures of the Golgi-impregnated and gold-toned hippocampal neurons. In this report cholinergic synapses on the heads of small spines, the necks of large complex spines, dendritic shafts, and cell bodies of identified dentate granule cells are described. The variety of cholinergic synapses suggests that cholinergic transmission in the fascia dentata is a complex event.Next, the Golgi/EM technique was applied to Vibratome sections that contained retrogradely labeled neurons in the hilar region of the fascia dentata following horseradish peroxidase (HRP) injection into the contralateral hippocampus. With this combined approach some of the hilar cells projecting to the contralateral side were identified as mossy cells by the presence of retrogradely transported HRP in thin sections through these Golgi-impregnated and gold-toned neurons. Our findings suggest that the mossy cells are part of the commissural/associational system terminating in the inner molecular layer of the fascia dentata. They are mainly driven by hilar collaterals of granule cell axons that form giant synapses on their dendrites.Finally, the Golgi/EM procedure was used to study the differentiation and developmental plasticity of hippocampal and dentate neurons in transplants and slice cultures of hippocampus. Under both experimental conditions, the differentiating neurons are deprived of their normal laminated afferent innervation but develop their major cell-specific characteristics including a large number of postsynaptic structures (spines). As revealed in thin sections of gold-toned identified cells, all these spines formed synapses with presynaptic boutons suggesting sprouting of the transplanted and cultured neurons, respectively.Altogether, the present report demonstrates the usefulness of the Golgi/EM technique, particularly of the section impregnation procedure, for a variety of studies requiring the identification of individual neurons at the ultrastructural level. © 1992 Wiley-Liss, Inc.
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    New initiatives in quantitative morphology (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 2-2 
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    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200103
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    Nickel nitrate: A new junction permeability tracer for the study of the blood-testis barrier (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 34-42 
    Details
    ISSN: 1059-910X
    Keywords: Intercellular tracer ; Lanthanum ; Testis ; Galea ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: With the purpose of evaluating a new intercellular tracer, nickel-K ferrocyanide, we compared results yielded by lanthanum with information provided by nickel. This was done in the seminiferous epithelium of Holtzman rats of several postnatal ages and in a wild local seasonal breeder Galea musteloides. Tissues were studied with transmission electron microscopy and freezefracture replications. Nickel tracing proved to delineate cell contours more intensely and less interruptedly than lanthanum. With regard to seasonal variations in adult galea, the limits of the barrier were similar to those described in other mammals: spermatogonia, preleptotene, and leptotene spermatocytes were surrounded by the tracer in the basal compartment. The zygotenepachytenes were contained in the lumenal compartment and tracers were stopped at the inter - Sertoli cell tight junctions. During the inactive spermatogenic phase in winter, the seminiferous epithelium contained Sertoli cells and occasional germ cells, never beyond the spermatocyte stage. The tracer filled intercellular spaces, indicating that the barrier was incompetent. Some resting germ cells showed nuclear hyperchromasia, karyolysis, organelle loss, cell shrinkage, and cell fusion leading to a multinucleated cells. The inter-Sertoli tight junctions were scanty and had randomly oriented and discontinuous junctional strands. Moreover, inter - Sertoli cell gap junctions proliferated. During the active spermatogenic phase in summer, junctions were numerous. Their junctional strands were parallel to each other, and continuous.
    Additional Material: 18 Ill.
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    Effects of vitamin A deficiency on the inter - Sertoli cell tight junctions and on the germ cell population (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 43-49 
    Details
    ISSN: 1059-910X
    Keywords: Vitamin A deficiency ; Blood-testis barrier ; Seminiferous epithelium ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: When 20-day-old rats are placed on a vitamin A deficient diet (VAD) for a period of 10 weeks, the seminiferous tubules are found to contain only Sertoli cells, a few residual A0, A1 spermatogonia, and preleptotene spermatocytes (PL). The type A1 spermatogonia and PL spermatocytes are arrested in their G2 phase. In VAD rats type A2-A4, intermediate (In) and B spermatogonia and all types of spermatocytes (except PL spermatocytes) and spermatids are eliminated from the seminiferous tubules. Two questions were raised in this investigation: (1) Is there, in VAD rats, any correlation between a breakdown of the blood-testis barrier (e.g., Sertoli cell tight junctions) and germ cell loss? (2) Is the disappearance of most germinal cells due to their degeneration during spermatogenesis or to a maturation depletion process resulting from an arrest of spermatogenesis at the spermatogonial stage? To investigate these questions four groups of male Sprague-Dawley rats (20-days old) were fed a VAD diet for 7 to 12 weeks. The testes were fixed by perfusion with 2.5% glutaraldehyde in 0.1 M sodium cacodylate containing 2% lanthanum nitrate, an electron opaque tracer used to test the patency of Sertoli cell tight junctions. The lanthanum permeated the intercellular space of the basal compartment but was arrested by normal inter - Sertoli cell tight junctions. The seminiferous epithelium showed numerous degenerating germ cells, some being internalized by Sertoli cells as membrane-bound phagosomes. Thus, these results indicate firstly that inter - Sertoli cell tight junctions remain intact during vitamin A deficiency, and secondly that in a first phase nonviable germinal cells degenerate during spermatogenesis and their residues are actively phagocytosed by Sertoli cells followed by a second phase where the regressed state of the seminiferous epithelium is maintained by a maturation depletion condition resulting from an arrest of spermatogonial proliferation and differentation.
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    Fundamental electron and ion beam interactions with solids for microscopy, microanalysis and microlithography. Scanning microscopy supplement 4, edited by Jergen Schou, Pieter Kruit, and Dale Newbury. Scanning Microscopy International, AMF O'Hare, Chicago, Illinois, 1990, 379 pp, $59.00 (USA), $64.00 (elsewhere) (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 102-102 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200111
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    The blood-testis barrier and sertoli cell junctions: Structural considerations (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 3-33 
    Details
    ISSN: 1059-910X
    Keywords: Sertoli cell ; Tight junction ; Gap junction ; Adhering junction ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In this review, a few well-established axioms have been challenged while others were viewed from a new perspective. The extensive literature on the blood-testis barrier has been scrutinized to help probe its mechanics and hopefully to promote understanding of the constant adaptation of the barrier function to germ cell development. Our principal conclusions are as follows: (1) Although the barrier zonule is topographically located at the base of the seminiferous epithelium it actually encircles the apex of the Sertoli cell. Consequently the long irregular processes specialized in holding and shaping the developing germ cells should be considered as apical appendages analogous to microvilli. (2) The development of the barrier zonule does not coincide with the appearance of a particular class of germ cells. (3) The barrier compartmentalizes the epithelium into only two cellular compartments: basal and lumenal. (4) Although the blood-testis barrier does sequester germ cells usually considered antigenic, immunoregulator factors other than the physical barrier seem to be involved in preventing autoimmune orchitis. (5) Structurally, a Sertoli cell junctional complex is composed of occluding, gap, close, and adhering junctions. The Sertoli cell membrane segments facing germ cells are presumably included in the continuum of the Sertoli cell junctional complex that extends all over the lateral and apical Sertoli cell membranes. (6) The modulation (i.e., formation and dismantling) of the junctions in a baso-apical direction is characteristic of the seminiferous epithelium and may be dictated by germ cell differentiation. The formation of tubulobulbar complexes and the following internalization of junction vesicles conceivably represent sequential steps of a single intricate junction elimination process that involves junction membrane segments from different cell types as part of a continual cell membrane recycling system. (7) The preferential association of junctional particles with one or the other fracture-face reflect a response to various stimuli including seasonal breeding. Changes in the affinity of the particles are generally coincidental with cytoskeletal changes. However, changes in the cytoskeleton are not necessarily accompanied by permeability changes. The number of strands seems to reflect neither the junctional permeability nor the transepithelial resistance. The diverse orientation of the strands seems to be related to the plasticity of the Sertoli cell occluding zonule. (8) Cooperation between all constituents (Sertoli cells, myoid cells, cell substratum, and germ cells) of the epithelium seems essential for the barrier zonule to function in synchrony with the germ cell differentiation. This cooperation ensures that the Sertoli cell barrier zonule is able to continually adapt to the changing requirements of spermatogenesis.
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    A temperature-jump device for time-resolved cryo-transmission electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 95-101 
    Details
    ISSN: 1059-910X
    Keywords: Phosphatidylcholine ; Docosane ; Kinetics ; Phase transitions ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: We describe a temperature-jump device that permits time-resolved studies of thin cryo-transmission electron microscopy specimens. The specimen is rapidly heated to induce a change in microstructure just prior to cryo-fixation. The apparatus consists of a xenon arc lamp equipped with a shutter controlled by timing circuitry, used in conjunction with an environmental specimen preparation chamber. The specimen is heated by exposure to focused light from the lamp, and then plunged into cryogen. Using a thermocouple constructed from an electron microscope grid, we show that temperature jumps of 30-60 K are achieved with exposure times of 150-450 milliseconds. Micrographs of dimyristoyl phosphatidylcholine (DMPC) vesicles and n-docosane films, subjected to these exposures, shew that the specimens are still at least 20-30 K above their initial temperature when they contact the cryogen. This method could be applied to a variety of biological and chemical systems which undergo structural changes activated by a rise in temperature.
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    Designing multi-viscosity embedding media utilizing novel resin/anhydride/catalyst combinations (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 105-106 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
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    URL: http://dx.doi.org/10.1002/jemt.1070200113
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    Ultrarapid freezing on a diamond surface (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 103-104 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200112
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    Use of ultrastructural immunohistochemistry in human pituitary pathology (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 152-161 
    Details
    ISSN: 1059-910X
    Keywords: Pre-embedding method ; Post-embedding method ; Non-embedding method ; Protein A-gold technique ; Double labeling ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Recent advances in ultrastructural immunohistochemistry have provided insight into not only the subcellular localization of single antigens but also the colocalization of two distinct antigens in the same cellular constituent. In the field of pituitary pathology, precise identification of cell types, mechanism of processing, and dynamic intracellular transportation of hormones, as well as produciton of multiple hormones in the same cells of nontumorous and neoplastic adenohypophyses, have been documented by use of these techniques. The present review deals with the use of major methods for ultrastructural immunohistochemistry including pre-, post-, and non-embedding methods, paricularly focusing on their application to human pituitary pathology. Problems of tissue processing and a protocol for double labeling technique using the protein A-gold complex are also described.
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    Effect of drugs on pituitary ultrastructure (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 162-176 
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    ISSN: 1059-910X
    Keywords: Drug effects ; Anterior pituitary ; Light and electron microscopic structure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Various drugs and hormones influence the light microscopic and especially the electron microscopic structure of the anterior pituitary and its tumors. Many structural effects are known only from animal experiment since specimens from human pituitaries are mostly not available. The structure of growth hormone (GH) Cells is relatively stable. A massive GH cell hyperplasia is known only in rare cases with growth hormone releasing factor (GRF) excess from tumors. Prolactin cells can be stimulated by drugs, neurotransmitters, and hormones which decrease the dopamine inhibition. Adrenocorticotropic hormone (ACTH) cells are stimulated by stress, some hormones, loss of adrenals, and drugs which activate the α1- and β-redceptors or inhibit the α2-receptors. They are suppressed and changed into Crook's cells by treatment with glucocorticoids. Thyroid-stimulating hormone (TSH) cells increase in number and size in states of over-stimulation especially by thyrotropin releasing hormone (TRH). A decrease results from hyperthyroidism and possibly from somatostatin, L-dopa, and dopamine. Gonadotroph cells transform into castration cells in strongly hyperactive states (gonadectomy, antiandrogens, gonadotropin releasing hormone [Gn-RH]agonists, aminoglutethimide). Special types of pituitary adenomas can be treated with drugs which suppress hormone production and proliferation. Dopamine agonists and somatostatin reduce the tumor size of varying proportions of GH secreting adenomas in acromegaly. Ultrastructurally, a decrease of cytoplasmic and nuclear volume and an increase of lysosomes are found. Bromocriptine and other dopamine agonists are establiched in the treatment of prolactin secreting adenomas. They induce a shrinkage in many cases. Ultrastructurally, a reduction of cellular and nuclear size, an increase in number of secretory granules and of lysosomes, and a reduction of rough endoplasmic reticulum can be demonstrated.
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    Atom probe microanalysis: Principles and appilcations to materials problems, by M.K. Miller and G.D.W. Smith. Materials Research Society, Pittsburgh, 1989, 278 pp, $47.00 (US), $56.00 (foreign) (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 217-217 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200209
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    Polymorphism of a long-chain cycloparaffin (CH2)120 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 205-216 
    Details
    ISSN: 1059-910X
    Keywords: Crystallization ; Morphology ; Epitaxy ; RuO4 Staining ; Surface Decoration ; TEM ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The polymorphism of a long-chain cycloparaffin (CH2)120 and chain packing in its crystals were discussed on the basis of some results obtained mainly by transmission electron microscopy. Monoclinic and orthorhombic single crystals of (CH2)120 were isothermally grown together from a dilute solution in p-xylene. Lozenge-shaped orthorhombic single crystals were more frequently observed than lath-shaped monoclinic ones. The basal surfaces of orthorhombic and monoclinic single crystal platelets wore decorated with vapor-deposited polyethylene [PE]. Orthorhombic single crystals of (CH2)120 with the (110) twin boundary and monoclinic ones with the (100) twin boundary were also observed.Rod-like edge-on crystals of (CH2)120 were grown from a dilute p-xylene solution onto the (001) surface of alkali halides. The crystal system of the (CH2)120 edge-on crystals depended on the kind of substrate. The monoclinic crystal was grown on NaCl, the orthorhombic one on KBr and KC1. The monoclinic form of (CH2)120 edge-on crystal was transformed to the orthorhombic one by annealing on NaCl. In both monoclinic and orthorhombic edge-on crystals, the molecular plane determined by two zigzag stems in a molecule of (CH2)120 was parallel to the substrate surface and the molecular axis (crystallographic c-axis) was perpendicular to the longer side of the rod-like edge-on crystals. The sub-cell dimensions of the stem chains in both forms of (CH2)120 crystals were very similar to those of monoclinic and crthorhombic PE crystals, respectively.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200208
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    Characterization of Sertoli cell perinuclear filaments (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 219-231 
    Details
    ISSN: 1059-910X
    Keywords: Sertoli cell ; Nucleus ; Cytoskeleton ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Sertoli cell nuclei are characterized by deep invaginations and, in addition, the orientation of the nuclei with respect to the wall of the seminiferous tubules varies during the cycle of the seminiferous epithelium. These events may be the result of cytoplasmic filaments acting at the level of the nuclear capsule and may represent significant changes in Sertoli cell activity. Thus, a study was performed to characterize the nature of the perinuclear filaments of Sertoli cells in vivo and in vitro.In Sertoli cells in vivo, microtubules and microfilaments were often detected in the perinuclear cytoplasm, and these cytoskeletal components were observed to course either parallel to, or abut at, the nuclear capsule. In Sertoli cells in vitro, the nuclear infoldings are retained and the perinuclear cytoskeleton was shown to contain microtubules, f-actin, and intermediate filaments. A fixation-permeabilization protocol employing tannic acid-saponin was used and it significantly enhanced the preservation of cytoskeletal components. The presence of f-actin was demonstrated by using the S1 fragment of muscle myosin to decorate the microfilaments. Treatment of the cultured cells with either microtubule or f-actin depolymerizing agents had no effect on nuclear shape. Thus, at present, the function of the prominent perinuclear cytoskeletal components remains unknown.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200302
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    Improved structural detail in freeze-fracture replicas: High-angle shadowing of gap junctions cooled below -170°C and protected by liquid nitrogen - cooled shrouds (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 187-204 
    Details
    ISSN: 1059-910X
    Keywords: Complementarity ; Elastic deformations ; Gap junctions ; Plastic deformation ; Pre-fracturing ; Shrouding ; Water vapor contamination ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In conventional freeze-fracture replicas, precise complementarity of membrane faces is seldom achieved. In a model system frequently used to evaluate replica quality, vertebrate gap junctions are usually visualized as patches of 8-10 nm P-face intramembrane particles separated by 1-2 nm spaces, while E-face images are represented by 4-6 nm conical pits separated by 5-7 nm wide membrane ridges. However, that disparity in sizes of particles versus pits, as well as the disparity in the widths of the spaces separating particles versus pits, suggests that a significant reduction in complementarity of membrane faces has occurred. In this investigation, a JEOL JFD-9000 freeze-etch machine was modified so that fracturing and replication could be performed at temperatures much colder than commonly employed. With the addition of cryopumps to improve overall vacuum and the installation of optically tight LN2-cooled shrouds surrounding the specimen and the knife, water vapor contamination arising from all sources within the vacuum chamber was reduced substantially, allowing replicas to be made at temperatures down to -185°C. With the specimen at these much colder temperatures, water vapor released by the heat of cleaving was also reduced significantly, providing additional improvement in replica quality. In addition, with higher shadowing angles (〈 60°) and with the specimen at a much lower temperature, the grain size of the platinum film was noticeably reduced, thereby improving resolution at the molecular level. Under these improved conditions, replicas of rat liver gap junctions revealed that many of the P-face IMPs were tubes 6-7 nm in diameter, but that other IMPs had been stretched and distorted by the fracturing process. More important, however, these high resolution replicas revealed that the replicas of the E-face pits represented three-dimensional molecular casts of the transmembrane proteins comprising the connexon hexamer. This means that before they were replicated, the E-face pits faithfully maintained the shape that the IMPs had before fracturing. These more detailed images revealed a new structure in the center of each E-face pit: a 2-3 nm “peg” that may represent the frozen aqueous matrix of the connexon ion channel that remained after elastic extraction of the surrounding six connexin molecules. Thus, high-angle shadowing at very low specimen temperature under virtually non-contaminating conditions has revealed a new level of detail for membrane structure in freeze-fracture replicas.
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    URL: http://dx.doi.org/10.1002/jemt.1070200207
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    Immunoelectron microscopical distribution of histones H2B and H3 and protamines in the course of mouse spermiogenesis (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 259-267 
    Details
    ISSN: 1059-910X
    Keywords: Ultrastructure ; Immunocytochemistry ; Chromatin structure ; Nuclear proteins ; Testis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: We have followed the fine structural distribution of two nucleosomal core histones, H2B and H3, and of protamines in the course of mouse spermiogenesis by means of specific antibodies and ultrastructural immunocytochemistry.Our results demonstrate that the nuclear labeling density of histone H2B decreases during steps 6-8 and then increases again in step 9-10 spermatids, while the labeling for histone H3 is constant throughout this period. In step 12 spermatids, the anti-H2B antibody labels mainly the central area of the nucleus. The first signs of protamine labeling are present in step 12 spermatids, where the gold grains can be found over the periphery of the nucleus. Later on, protamine labeling constantly increases and, by the end of spermiogenesis, the whole nucleus is labeled.We suggest that the morphological and structural differences between the central area and the periphery of mouse spermatids are, at least partly, due to a difference in the protein moiety associated with DNA. The central area, which is peculiar to the mouse and has been previously considered as a focus of chromatin condensation, represents, however, the last nuclear region containing histones and consequently the last area where the substitution of histones by protamines takes place.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200305
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    Masthead (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992) 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070220201
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    Introduction: The new challenge for biological scaning electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 129-129 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070220202
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    Sample preparation for electron microscopy of internal cell structure (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 151-159 
    Details
    ISSN: 1059-910X
    Keywords: High magnification scanning electron microscopy ; Rapid-freezing ; Deep-etch replicas ; Cell extraction ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Methods are reviewed for examination of internal cell structure by high-resolution scanning electron microscopy and compared with the rapid-freeze deep-etch replica technique used in transmission electron microscopy. Rapid freezing of fresh material, followed by freezefracture, provides a theoretically attractive approach in ultrastructure studies, but the high protein and solute content of most cells prevents a deep three-dimensional view for material frozen without some form of extraction. After discussion of other methods it is concluded that the most useful general approach, at least for cultured cells, is to first permeabilize or break open the cells in a medium which preserves the structure under study in a functional state as, for example, the movement of chromosomes along the division spindle, or transport of proteins within the Golgi region. After permeabilization, with attendant partial extraction, the preparation can be fixed, then viewed by either deep-etch replication, or by high-resolution scanning electron microscopy, with structure of interest revealed in deep view. © 1992 Wiley-Liss, Inc.
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    Freeze-substitution of chemically stabilized samples for biological field emission scanning electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 170-184 
    Details
    ISSN: 1059-910X
    Keywords: Freeze-substitution ; Osmium impregnation ; Lipid stabilization ; P-tube technology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The high resolution imaging capabilities of modern field emission scanning electron microscopes require adequately improved tissue preparation procedures to prevent the collapse of macromolecular structures and the extraction of molecules. A routine cryo-stabilization technique is described which utilizes chemical crosslinking and cryo-dehydration for mechanical and chemical stabilization of protein and lipid structures and increase of electrical conductivity of the sample. Thiocarbohydrazide (TCH) serves as a general mordant for osmium tetroxide crosslinking. However, extensive washing after all impregnation steps is necessary to dissolve unspecific osmium black precipitations at the sample surface. Collagen I aggregates showed increased stability against collapse after TCH osmification alone, whereas pulmonary surfactant liposomes require additional freeze-substitution in methanol and Freon 113 for stabilization during critical point drying. Environmental scanning electron microscopy (at water vapor pressures of 5-10 torr within the specimen chamber) was used to control, in the wet phase, the stabilization procedure at the level of chemical crosslinkage. It could be confirmed that tannic acid, often used to stabilize lipids, eads to artificial rearrangement of bilayered liposomes into compact presumable multilayered bodies, whereas the TCH osmification preserved liposome structures and their aggregates. The increase of electrical conductivity of sliced tissue was demonstrated on kidney. Support technologies for the cryo-stabilization procedures are described in detail, as well as simple routines for first stabilization trials with new samples. On pulmonary tissue, the excellent preservation of alveolar shape and fine structures of intermediate forms of surfactant are described. © 1992 Wiley-Liss, Inc.
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    Technique of reflection electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 318-332 
    Details
    ISSN: 1059-910X
    Keywords: RHEED ; Surface steps ; REM ; Surface defects ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Details of the technique of reflection electron microscopy (REM) are described. Step by step instruction is given on how to do it on an ordinary electron microscope. Also given are some specimen preparation techniques and strategy of REM investigation.
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    Introduction (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 317-317 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200402
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    From egg to pole cells: Ultrastructural aspects of early cleavage and germ cell determination in insects (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 49-74 
    Details
    ISSN: 1059-910X
    Keywords: Egg activation ; Syngamy ; Karyogamy ; Gonomery ; Ooplasmic system ; Blastoderm ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Insect eggs are giant and very complex cells covered by an extremely resistant shell. Both the egg cell and surrounding eggshell express anteroposterior and ventrodorsal polarity. The molecular and cytoplasmic organization of both axes originates during oogenesis and leads to the production of an ooplasmic system which consists of euplasm and deutoplasm (yolk) and contains a nucleus as well as extranuclear determinants of maternal origin. Both are part of the store of information for early embryogenesis. In addition, the deutoplasm serves as raw material and early nutrient supply for building the embryo. The insect egg cell, which is arrested in the first maturation division when released from the ovary during oviposition, will be activated by different stimuli among different species to complete meiosis and start embryogenesis. The zygote nucleus undergoes a number of synchronous mitotic divisions leading to cleavage energids which initially form a syncytial blastoderm and subsequently the cellular blastoderm. In many insects, prior to blastoderm formation, polar granules (or oosome material) are incorporated in a single cell or a small number of cells which bud off at the posterior pole. These so called pole cells give rise to the primordial germ cells. Therefore, polar granules or the oosome material mark the germ line, and while structural counterparts of determinants of body pattern formation have so far not been found, the polar granules or oosome serve as an autonomous ooplasmic determinant for the pole or germ cells. Anteroposterior body polarity can arise independent of the germ plasm. © 1992 Wiley-Liss, Inc.
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    Proceedings of the eleventh annual meeting of the Alabama electron microscopy society held in Tuscaloosa, Alabama, March 18-19, 1992 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 126-127 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070220109
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    Recent studies of surface dynamic processes by reflection electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 333-340 
    Details
    ISSN: 1059-910X
    Keywords: Current induced surface structure ; Surface electromigration ; Alloyed adsorbate ; Oxidation of Si ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Reflection electron microscope studies of surface dynamic processes are reviewed and illustrated with recent new observations. They include: surface electromigration and current dependent structures of Si surfaces; surface etching by oxidation of Si surface; and growth of two dimensional alloyed adsorbate by co-deposition of metals on Si surface. The observations revealed details of the surface dynamic processes, which are difficult to obtain with other surface analysis techniques.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200404
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    Application of ultrahigh vacuum reflection electron microscopy for the study of clean silicon surfaces in sublimation, epitaxy, and phase transitions (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 341-351 
    Details
    ISSN: 1059-910X
    Keywords: Monoatomic step ; Superstructural transition ; Epitaxial growth ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The construction and performance of an ultrahigh vacuum reflection electron microscope (UHV REM) on the base of a transmission electron microscope with top entry stage are described. Some results of in situ study of structural transformations on clean silicon surfaces during sublimation, surface phase transitions, and initial stages of epitaxial growth are shown.
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    Degradation, amorphization, and recrystallization of ion bombarded si(111) surfaces studied by in situ reflection electron microscopy and reflection high energy electron diffraction techniques (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 352-359 
    Details
    ISSN: 1059-910X
    Keywords: Reflected beam ; Amorphization ; Ion bombardment ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In this paper we report the effect of noble gas ions bombardment on the degradation of atomically flat Si(111) surfaces at room and high (400°C - 600°C) temperatures. Reflection high energy electron diffraction (RHEED) and reflection electron microscopy (REM) have been used to characterize the topography and structure of the as-implanted and post annealed surface layers. It is shown that the fading of the specularly reflected beam is not directly related to the amorphization of the surface. This experimental study has also evidenced the difficulties one meets to regrow a defect-free material after amorphization by noble gas bombardment. For high temperature for which the amorphization is not possible, the surface loses its stepped structure and turns into a monocrystalline but atomically rough surface. This roughness is a function of substrate temperature.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200406
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    Bloch wave treatment of symmetry and multiple beam cases in reflection high energy electron diffraction and reflection electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 360-370 
    Details
    ISSN: 1059-910X
    Keywords: RHEED ; Bloch waves ; Green function ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Bloch wave equations for the multiple beam cases in reflection high energy electron diffraction (RHEED) are derived from the integral equation by forward- and back-scattering Green function operators. A linearization is achieved through separation in a forward- and a back-scattering component for each beam. This leads to a set of fundamental equations similar to the transmission case, but with a non-Hermitian matrix, and the beams may be entered as either forward-, back-scattered, or both. The number of beams needed to be included in RHEED calculations is thus reduced, and so are the computing time and computer space required. The systematic row case, corresponding to reflections from planes parallel to the crystal surface, is treated in detail and illustrated by calculations of dispersion surfaces and rocking curves for Au(001). Symmetry relations for the systematic row and between reciprocal rows are discussed and illustrated.
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    Developments in the dynamical theory of high energy electron reflection (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 371-389 
    Details
    ISSN: 1059-910X
    Keywords: Bloch wave method ; Crystal surfaces ; Multislice ; Surface science ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: High energy electron reflection (HEER) is an important technique in surface science and uses the information carried by high energy electrons reflected from surfaces to study surface structures and surface electronic states. With the development of reflection high energy electron diffraction (RHEED), high energy electron microscopy (REM), and high energy electron energy loss spectroscopy (EEL) in surface science, the usefulness of HEER has been widely recognized and demonstrated. However, a stationary dynamical solution for an arbitrary surface for HEER has not been obtained yet.In this paper, some developments in understanding the dynamical theory of HEER, particularly in recent years, are reviewed: 1The introduction of the concept of current flow for a semi-infinite crystal model has removed the confusion around the wave points in the “band gap”.2The consistency between the Bloch wave and multislice in the Bragg case has verified the validity of the argument of current flow and led to the emergence of the BMCR method (Bloch wave + Multislice Combined for Reflection).3The failure of the Bloch Wave-Only solution (the BWO solution) on Au (110) surfaces in the Bragg case revealed by the BMCR method implies that previous BWO calculations in the Bragg case might be at fault.4The 2-D dependence of the electron wave fields and Picard iteration-like character of multislice calculation in the Bragg case has led to the emergence of an Edge Patching method in Multislice-mode-Only (the EPMO method). The new method yields an infinitely convergent stationary dynamical solution for an arbitrary surface.
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    URL: http://dx.doi.org/10.1002/jemt.1070200408
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    Reflection electron energy-loss spectroscopy and imaging for surface studies in transmission electron microscopes (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 390-405 
    Details
    ISSN: 1059-910X
    Keywords: Reflection electron microscopy ; Secondary electron imaging ; Field emission gun ; In situ REM ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: A review is given on the techniques and applications of high-energy reflection electron energy-loss spectroscopy (REELS) and reflection electron microscopy (REM) for surface studies in scanning transmission electron microscopes (STEM) and conventional transmission electron microscopes (TEM). A diffraction method is introduced to identify a surface orientation in the geometry of REM. The surface dielectric response theory is presented and applied for studying α-alumina surfaces. Domains of the α-alumina (012) surface initially terminated with oxygen can be reduced by an intense electron beam to produce Al metal; the resistance to beam damage of surface domains initially terminated with Al+3 ions is attributed to the screening effect of adsorbed oxygen. Surface energy-loss near-edge structure (ELNES), extended energy-loss fine structure (EXELFS), and microanalysis using REELS are illustrated based on the studies of TiO2 and MgO. Effects of surface resonances (or channeling) on the REELS signal-to-background ratio are described. The REELS detection of a monolayer of oxygen adsorption on diamond (111) surfaces is reported.It is shown that phase contrast REM image content can be significantly increased with the use of a field emission gun (FEG). Phase contrast effects close to the core of a screw dislocation are discussed and the associated Fresnel fringes around a surface step are observed. Finally, an in situ REM experiment is described for studying atomic desorption and diffusion processes on α-alumina surfaces at temperatures of 1,300 - 1,400°C.
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    URL: http://dx.doi.org/10.1002/jemt.1070200409
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    Pinealocyte synaptic ribbons and neuroendocrine function (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 175-187 
    Details
    ISSN: 1059-910X
    Keywords: β-adrenergic receptor ; Development ; Isoproterenol ; Melatonin ; N-acetylserotonin ; Ribbon fields ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: A comparative study of pinealocyte synaptic ribbons (SR) revealed two predominant populations exhibiting either a rod/ribbon shape (SRr) or a spherical/punctate shape (SRsp). Species-specific differences were found in the abundance of SR, the ratio of SRr/SRsp, and the occurrence of SR in ribbon fields. The close topographical relationship of SR to the plasma membrane and the numerical changes that occurred with changes in metabolism of the pinealocytes suggest that SR have important vesicle-mediated interactions with the cell membrane. Experiments designed to clarify the relationship between SR and pineal neuroendocrine function revealed a positive correlation between SR numbers and indole intermediates during pineal development in the rat, and increased SR frequency after denervation of the rat pineal gland or administration of the β-adrenergic agonist, isoproterenol. These data are consistent with the hypothesis that SR function is linked to receptor mechanisms regulating indoleamine production in the pineal gland. © 1992 Wiley-Liss, Inc.
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    Third ventricular pineal gland grafts in the gerbil: An electron microscopical and immunohistochemical investigation (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 205-217 
    Details
    ISSN: 1059-910X
    Keywords: Pineal gland ; Grafts ; Transplants ; Gerbil ; Pinealocyte ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The superficial pineal gland was grafted into the third ventricle of adult mongolian gerbils. Donor pineal glands from both neonatal and 3-4 week old gerbils were able to survive for at least 6 months. The pinealocytes of the grafted superficial pineal glands maintained the morphology and the S-antigen immunoreactivity of the in situ pineal complex. Synaptic ribbons and spherules were present but rare. Unlike the in situ pinealocytes, glycogen accumulations were common in the graft pinealocytes. Site specific modulation of structure was indicated as the ventricular surface of the grafts became covered with cerebrospinal fluid (CSF)-contacting pinealocytes typical of those seen in the deep pineal. The CSF-contacting pinealocytes of the graft had numerous processes that extended along the ventricular surface of the graft. The blood vessels of the grafts had non-fenestrated endothelium and wide perivascular areas typical of those seen in the in situ pineal complex. Tyrosine hydroxylase-immunopositive nerve fibers were present in the grafted tissue indicating reinnervation of the graft. The source of the fibers was not determined. The nerve fibers were present both within the perivascular area and within the parenchyma where they were associated with pinealocytes. The results demonstrate that the cerebral ventricles are an ideal location for the survival of superficial pineal gland grafts. It is suggested that pineal grafts may be a means to further study pineal development and innervation. © 1992 Wiley-Liss, Inc.
    Additional Material: 18 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210304
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    Fine structure of the pinealopetal innervation of the mammalian pineal gland (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 188-204 
    Details
    ISSN: 1059-910X
    Keywords: Ultrastructure Central innervation ; Sympathetic ; Parasympathetic ; Neuropeptides ; Mammals ; Human fetus ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The mammalian pineal gland is innervated by peripheral sympathetic and parasympathetic nerve fibers as well as by nerve fibers originating in the central nervous system (central innervation). The perikarya of the sympathetic fibers are located in the superior cervical ganglia, while the fibers terminate in boutons containing small granular vesicles and a few large granular vesicles. Both noradrenaline and neuropeptide Y are contained in these neurons. The parasympathetic fibers originate from perikarya in the pterygopalatine ganglia. The neuropeptides, vasoactive intestinal peptide and peptide histidine isoleucine, are present in these fibers, the boutons of which contain small clear transmitter vesicles and larger granular vesicles. The fibers of the central innervation originate predominantly from perikarya located in hypothalamic and limbic forebrain structures as well as from perikarya in the optic system. These fibers terminate in boutons containing small clear and, in certain fibers, an abundant number of large granular vesicles. In rodents, the majority of the central fibers terminate in the deep pineal gland and the pineal stalk. From these areas impulses might be transmitted further caudally to the superficial pineal gland via neuronal structures or processes from pinealocytes. Several hypothalamic neuropeptides and monoamines might be contained in the central fibers.The intrapineal nerve fibers are located both in the perivascular spaces and intraparenchymally. The majority of the intraparenchymally located fibers terminate freely between the pinealocytes. However, some nerve terminals make synaptic contacts with the pinealocytes and in some species with intrapineal neurons.In fetal mammals, sympathetic, parasympathetic, and central fibers are also present. In addition, an unpaired nerve, connecting the caudal part of the pineal gland with the extreme rostral part of the mesencephalon, is present. This nerve is a homologue to the pineal nerve (nervus pinealis) observed in lower vertebrates. © 1992 Wiley-Liss, Inc.
    Additional Material: 33 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210303
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    Ultrastructural morphology and allergen detection in birch pollen after aqueous, anhydrous-liquid, and vapor fixation techniques (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 242-248 
    Details
    ISSN: 1059-910X
    Keywords: p-Formaldehyde ; Bet v I ; Glutaraldehyde ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In order to find a good compromise between preservation of ultrastructural morphology and retention of antigenicity, birch pollen grains were chemically fixed in aqueous p-formaldehyde or glutaraldehyde, in p-formaldehyde or glutaraldehyde dissolved in anhydrous glycerol, and in p-formaldehyde or glutaraldehyde vapor. Representative cytoplasmic areas were inspected for the preservation of ultrastructural morphology and for their capacity to bind a monoclonal antibody against Bet v I, the major birch pollen allergen. The experiments showed that cytoplasmic morphology was best preserved after vapor fixation in p-formaldehyde. This fixation also led to the highest degree of specific antibody binding. © 1992 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210307
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    Comparison of nuclear hydration in boar spermatozoa before and after freeze-thawing: Contrast analysis of cells embedded in bromide-labeled medium (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 249-254 
    Details
    ISSN: 1059-910X
    Keywords: Electron microscopy ; Water ; Image analysis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Epon labeled with bromide was used to embed ejaculated and freeze-thawed spermatozoa, with the hypothesis that it replaces most of cell water. Image analysis of relative contrasts between sperm nuclei and the surrounding medium revealed that when used in low concentrations, bromide is mostly absorbed to the nuclear structures. For higher concentrations, the chromatin is saturated, and the increase in contrast can be used to calculate relative differences in the hydration of nuclei. Boar sperm nuclei are more hydrated after freeze-thawing than before. © 1992 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210308
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    Masthead (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992) 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070210401
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    Immunocytochemistry and calcium cytochemistry of the mammalian pineal organ: A comparison with retina and submammalian pineal organs (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 227-241 
    Details
    ISSN: 1059-910X
    Keywords: Photoreceptors ; Photopigments ; Vitamin A ; S-antigen ; GABA ; Serotonin ; Calcium ions ; Corpora arenacea ; Synapses ; Neurohormonal terminals ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Morphologically the mammalian pineal organ is a part of the diencephalon. It represents a neural tissue histologically (“pineal nervous tissue”) and is dissimilar to endocrine glands. Submammalian pinealocytes resemble the photoreceptor cells of the retina, and some of their cytologic characteristics are preserved in the mammalian pinealocytes together with compounds demonstrable by cyto- and immunocyto-chemistry and participating in photochemical transduction. In our opinion, the main trend of today's literature on pineal functions - only considering the organ as a common endocrine gland - deviates from this structural and histochemical basis.In mammals, similar to the lower vertebrates, the pinealocytes have a sensory cilium developed to a different extent. The axonic processes of pinealocytes form ribbon-containing synapses on secondary pineal neurons, and/or neurohormonal terminals on the basal lamina of the surface of the pineal nervous tissue facing the perivascular spaces. Ribbon-containing axo-dendritic synapses were found in the rat, cat, guinea pig, ferret, and hedgehog. In the cat, we found GABA-immunoreactive interneurons, while the secondary nerve cells, whose axons enter the habenular commissure, were GABA-immunonegative. GABA-immunogoldylabeled axons run between pinealocytes and form axo-dendritic synapses on intrapineal neurons.There is a similarity between the light and electron microscopic localization of Ca ions in the mammalian and submammalian pineal organs and retina of various vertebrates. Calcium pyroantimonate deposits - showing the presence of Ca ions - were found in the outer segments of the pineal and retinal photoreceptors of the frog. In the rat and human pineal organ, calcium accumulated on the plasmalemma of pinealocytes and intercellularly among pinealocytes. The formation of pineal concrements in mammals may be connected to the high need for Ca exchange of the pinealocytes for their supposed receptor and effector functions. © 1992 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210306
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    Biological stereology: History, present state, future directions (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 255-261 
    Details
    ISSN: 1059-910X
    Keywords: Sterology ; Morphometry ; Quantitative morphology ; Computers ; Software ; Tutorials ; Simulations ; Databases ; Bio-Matrix Project ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The development of a quantitative structural platform for experimental biology - extending across a hierarchy of sizes ranging from molecules to organisms - has been punctuated by a series of major achievements over the last 30 years. Stereology, a form of quantitative morphology, has contributed handsomely to this success. A personal view is presented highlighting key events in the development of biological stereology. We also examine stereology with a view toward future developments in biology and speculate how stereology might contribute to the new biological infrastructure currently being built with computers. © 1992 Wiley-Liss, Inc.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070210402
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    An image processing/stereological analysis system for transmission electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 283-291 
    Details
    ISSN: 1059-910X
    Keywords: Computer imaging ; Cell ultrastructure ; Morphometry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: This study examines the feasibility of combining computer image digitization, image enhancement, and point counting stereological techniques to quantify video images from transmission electron microscopes (TEM). The essential hardware consists of an IBM PC/AT, a Matrox imaging board, a digitizing tablet, a high resolution black and white monitor, and a portable mass storage device. In addition a video camera must be mounted to the TEM. The software is written in three modules which have numerous routines for image acquisition, enhancement, and quantification. Quantification is achieved by selecting an electronic lattice and superimposing it on the cell image. A cursor is moved on the lattice (via the digitizing tablet) and the points are entered into a spreadsheet. One of the major limitations of the system was the reduced resolution inherent in the current hardware. However, sampling experiments showed that one could compensate for the reduced resolution by increasing the magnification of the digitized images, and the stereological values from digitized images compared favorably to those from electron micrographs. Furthermore, the system proved advantageous by eliminating the usual darkroom work, and in enhancing low contrast tissue. In spite of several hardware limitations, the concept of quantifying computer digitized TEM images appears promising. © 1992 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210405
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    Computer-assisted morphometry: Point, intersection, and profile counting and three-dimensional reconstruction (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 262-270 
    Details
    ISSN: 1059-910X
    Keywords: Stereology ; Software ; Coordinate geometry ; Volume density, Surface density ; Numerical density ; Serial sections ; Light microscopy ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The use of computers in morphometry can involve (1) automated image analysis, semiautomated image analysis and point, intersection, intercept and profile counts of two-dimensional images on tissue sections with mathematical extrapolation to the third dimension, (2) direct measurement of volumes, surfaces, lengths, and curvature using x,y,z coordinates of serial sectioned images, or (3) stereologic techniques and serial sections which is a combination of 1 and 2 above. Automated and semiautomated image analysis are generally restricted to specimens that are characterized by differential contrast such as interalveolar septa in the lung or histochemically stained mucous granules in pulmonary epithelium. Point, intersection, and profile counts using hand-held, notebook PCs, portable PCs, or standard PCs and MS-DOS - based application programs are extremely efficient, precise, affordable, and convenient methods of quantitating average values of a population. When morphometric measurements of individual structures are required, computer-assisted three-dimensional reconstruction using x,y,z coordinates of the surface outline from serial sections is a tedious yet precise method. We describe a computer program that efficiently estimates mean caliper diameter, volume, and surface area with less than five percent error with five sections per structure. We also describe a program that does digital image subtraction on serial sections, superimposes digitally generated test systems on biological images, and accumulates point, intersection, and profile counts using a Macintosh II series computer. © 1992 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210403
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    Application of automatic image analysis for quantitative morphological studies of peroxisomes in rat liver in conjunction with cytochemical staining with 3-3′-diaminobenzidine and immunocytochemistry (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 271-282 
    Details
    ISSN: 1059-910X
    Keywords: Peroxisomes ; Morphometry ; Protein A-gold ; Hypolipidemic drugs ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: We describe the application of automatic image analysis for quantitative morphological studies of peroxisomes in rat liver. For automatic detection by light and electron microscopy peroxisomes must be stained with the alkaline DAB procedure for catalase. There is a good agreement between the results obtained by conventional morphometric techniques and by automatic image analysis of DAB-stained electron microscopic preparations. Moreover, the image analyzer may be used in conjunction with a light microscope for evaluation of semithin sections (1-0.25 μm), provided the section thickness factor is taken into consideration. This latter approach has proven highly efficient in estimation of peroxisome proliferation. The limitations of this method and the relevance of volume density as a reliable morphometric parameter for evaluation of peroxisome proliferation are discussed. In the second part of this study we present the application of image analysis for quantitation of alterations of individual peroxisomal enzyme proteins after treatment with bezafibrate in immunogold stained ultrathin sections. There is good agreement between the results of quantitative immunocytochemistry and Western (immuno) blot analysis of highly purified peroxisomal fractions. In our experience quantitative immunoelectron microscopy provides a versatile, highly sensitive, and efficient method for detection of modulations of various proteins in peroxisomes. Finally the limitations and prospects of quantitative immunocytochemistry for investigation of peroxisomal proteins are discussed. © 1992 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210404
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    Section staining for electron microscopy using tannic acid as a mordant: A simple method for visualization of glycogen and collagen (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 65-72 
    Details
    ISSN: 1059-910X
    Keywords: Section mordanting ; Tannic acid mordanting ; Staining compounds ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The possibility that tannic acid and other classical mordants can be used in the electron microscopial section staining technique has been tested. A mordant can be defined as a chemical that combines with both a certain specific tissue component and the staining substance and thereby permits a staining reaction that otherwise will not be obtained. The following features were found to characterize section staining of tannic acid mordanted sections. Tannic acid apparently blocks those sites that normally would be contrasted by uranyl acetate or some other staining compounds. Ribosomes remain unstained. Glycogen particles, on the other hand, were stianed, whereas they are not in non-mordanted sections. In fact, glycogen was the only cytoplasmic component to be contrasted by the uranyl acetate, and collagen the only extracellular component. Several different section staining solutions gave the same staining patterns of examined cells and tissues. Specificity of the reaction thus seems to depend on the mordant rather than on the heavy atom section stain. Some other tested mordants, which have also been used in the light microscopical technique, did not give any useful new information.
    Additional Material: 26 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210110
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    Masthead (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992) 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070210201
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    Introduction (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 83-83 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070210202
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    Proceedings of the fourth meeting of the Great Lakes electron microscopy affiliates held in Cleveland, Ohio, October 17-19, 1991 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 77-81 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070210113
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