ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (23)
  • Freeze-fracture  (22)
  • Biochemistry
  • Wiley-Blackwell  (23)
  • Blackwell Publishing Ltd
  • Rostov-on-Don, Russia
  • Natural Sciences in General  (23)
  • 1
    Electronic Resource
    Electronic Resource
    Spatial organization of cardiac gap junctions can affect access resistance (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 31 (1995), S. 446-451 
    Details
    ISSN: 1059-910X
    Keywords: Freeze-fracture ; Confocal microscopy ; Gap junction channels ; Mathematical analytical model ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In the heart, gap junctions electrically couple myocytes together. Electron- and light-microscope-based analyses have revealed that cardiac gap junctions show a variety of organizational patterns. At the level of gap-junctional channel aggregates, freeze fracture has demonstrated diverse channel packing arrangements in the membranes of different myocardial tissues. Ultrastructural and immunohistochemical studies have shown variation and specialization in the 3-dimensional spatial distribution of gap junctional contacts between different types of myocardial cells. Here, we estimate the access resistance of various configurations of gap junctions using physical principles and explore how certain of these specializations in gap-junctional organization may influence access resistance, a potentially important determinant of electrical conductance between coupled myocardial cells. © 1995 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070310513
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Rapid primary microwave-glutaraldehyde fixation preserves the plasma membrane and intracellular structures of the protozoan Tritrichomonas foetus (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 25 (1993), S. 286-290 
    Details
    ISSN: 1059-910X
    Keywords: Microwave fixation ; Freeze-fracture ; Electron microscopy ; Protozoan ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Tritrichomonas foetus, a pathogenic protozoan, was used as a model to analyse microwave-stimulated fixation as a procedure of preparation of biological samples for electron microscopy of thin sections and freeze-fracture replicas. Good preservation of the protozoan structure was achieved by microwave-stimulated fixation and Epon polymerization. The membrane structure, as visualized in freeze-fracture replicas, was well preserved. © 1993 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070250404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Rapid freezing replica studies of membrane specializations in the proximal tubules of mouse kidney (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 24 (1993), S. 521-526 
    Details
    ISSN: 1059-910X
    Keywords: Membrane particle ; Freeze-fracture ; Deep-etch replica ; Apical tubule ; Kidney ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The membrane specializations of the fresh unfixed kidney cortex of adult and neonatal ICR mice were examined by using rapid freezing replica methods. In proximal tubular cells, numerous apical intracellular tubules exhibited helical patterns on the E face with a pitch of about 12 nm. This regular pattern was often continuous with similar striped indentations on the edge of the vacuoles connecting with the tubules. On the luminal surface (ES) of these vacuoles, membrane surface particles were arranged regularly in striped patterns with a center-to-center spacing of about 12 nm. We could not identify differentiations on the PF or PS of the same membrane systems. Another membrane specialization was a plaque or patch of clear pits in tilted lattice alignments on the P face of the large vacuoles with a center-to-center spacing of about 20 nm. This type of specialization was often observed in the neonatal mice proximal tubular cells. These membrane specializations may indicate the active membrane functions in the proximal tubules and suggest the functional continuity and structural relationship of these apical endocytic membrane systems. © 1993 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070240609
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Fine structure of Tritrichomonas foetus as seen using cryotechniques (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 29 (1994), S. 37-46 
    Details
    ISSN: 1059-910X
    Keywords: Tritrichomonas foetus ; Freeze-fracture ; Electron microscopy ; Fast-freezing fixation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Tritrichomonas foetus was studied using different physical and chemical fixation methods such as fast-freezing (by high pressure, “slam-freezing,” and jet-propane), freeze-substitution, conventional freeze-fracture and deep-etching, cryoultramicrotomy, and routine preparation for transmission electron microscopy. The use of fast-freezing fixation (FFF) proved to be superior in terms of structural preservation due to the rapidity of this fixation compared to that obtained using conventional chemical fixation. The low temperature techniques used here were useful to confirm data already obtained by conventional freeze-fracture using chemical fixation and cryoprotection, such as the presence of flagellar rosettes and costa structure. Cryoultramicrotomy and slam-freezing also demonstrated the presence of hair-like structures projecting out from the protozoan surface. New aspects of organelles of T. foetus were demonstrated. Published 1994 by Wiley-Liss, Inc.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070290106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Freeze-fracture study of cell junctions in the epididymis and vas deferens of a seasonal breeder: The mink (Mustela vison) (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 30 (1995), S. 37-53 
    Details
    ISSN: 1059-910X
    Keywords: Tight junctions ; Epididymis ; Vas deferens ; Freeze-fracture ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The present study used the freeze-fracture technique and vascular infusion of horseradish peroxidase (HRP) as a junction permeability tracer, visible in thin sections, to investigate potential seasonal variations in the mink epididymis and vas deferens cell junctions. The junctions were studied in kits during the neonatal period, during and after puberty, and during adulthood monthly throughout the annual reproductive cycle. Results showed the existence, at the time of birth, of a junctional complex joining ductal cells that reached the lumen of the epididymis and vas deferens. The lumenal impermeable segment of the junctional complex was characterized by the presence of an occluding zonule made up of continuous tight junctional ridges extending around the perimeter of the cell. The basal permeable segment of the junctional complex contained mainly discontinuous ridges with frequent forming gap and tight junctions next to adhering junctions. Receding annular junctions were present in the apical and lateral cytoplasm of principal and clear cells. The membrane domain apical to the occluding zonule bore 30-35 nm exo/endocytosis blebs and 40-60 crenations associated with deforming tight and gap junctions made up of randomly scattered particles. Patterns of junctional strands varied greatly from one principal and/or clear cell to another. However, cell junctions did not significantly vary from the neonatal period to adulthood nor from breeding to testicular regression. Anatomical subdivisions of the epididymis with fewer junctional strands per zonule and high diversity in their patterns exhibit no permeability differences to HRP when compared with subdivisions containing more numerous strands. The junctions were impermeable during the neonatal period and throughout the annual reproductive cycle. The following conclusions were reached: (1) a competent occluding zonule developed in the mink epididymis and vas deferens before it did in the testis; (2) the number of strands and the diversity of patterns did not correlate with permeability differences; (3) after the development of a lumen in the testicular excurrent duct, neither receding cellular changes caused by testicular regression nor seasonal passage of a bolus of sperm through the duct modified the occluding zonules; and (4) in the testicular excurrent duct, junction modulation (i.e., formation and deformation) paralleled that in the testis and followed the direction of the synthesis-transport-secretion process. © 1995 Wiley-Liss, Inc.
    Additional Material: 24 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070300104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Fracture - Permeation: A technique to assess cytoplasm compactness after glutaraldehyde-fixation (1986)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 4 (1986), S. 385-397 
    Details
    ISSN: 0741-0581
    Keywords: Freeze-fracture ; Ferritin ; Cytoplasmic matrix ; glutaraldehyde ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: We have developed a method - “fracture-permeation” - to assess the compactness of the cytoplasm in glutaraldehyde-fixed cells. Cells or tissues are fixed in glutaraldehyde, impregnated with glycerol, and frozen in liquid nitrogen. The cells are freeze-fractured, thawed, deglycerinated, and immersed in concentrated solutions of globular proteins. In initial experiments, we used native ferritin (NF) to permeate model matrices made of bovine serum albumin (BSA). We show that permeation depends on the concentraion of proteins within the cross-linked matrix: NF permeates matrices made from 10 or 15% (w/v) BSA solutions but do not permeate matrices made from solutions with 20% (w/v) protein or more. With freeze-fractured cells, ferritin molecules were unable to permeate the cross-linked cytoplasm of fungal zoospores and cysts, used here as examples of resting cells. In human lymphocytes from peripheral blood, permeation of ferritin was limited or absent, but it became massive in cells activated by phytohemagglutinin. Massive permeation of ferritin was also observed within the cytoplasmic matrix of other active cells (fungal sporangia, germinating cysts). In the examined resting cells, glutaraldehyde crosslinks the proteins into a dense matrix that effectively excludes ferritin (diameter 12 nm). These findings cannot be explained by models that envisage all cytoplasmic proteins congregated into a single-phase microtrabecular lattice with the nature and dimensions proposed by Porter and co-workers. We conclude that compactness of the cytoplasm matrix depends on the physiological state of the cell: It varies through differentiation and is related to the degree of cellular activity.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060040409
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Structural and functional correlates of synaptic transmission in the vertebrate neuromuscular junction (1988)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 10 (1988), S. 153-185 
    Details
    ISSN: 0741-0581
    Keywords: Acetylcholine receptor ; Active zones ; Endocytosis ; Exocytosis ; Freeze-fracture ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Because vertebrate neuromuscular junctions are readily accessible for experimental manipulation, they have provided a superb model in which to examine and test functional correlates of chemical synaptic transmission. In the neuromuscular synapse, acetylcholine receptors have been localized to the crests of the junctional folds and visualized by a variety of ultrastructural techniques. By using ultrarapid freezing techniques with a temporal resolution of less than 1 msec, quantal transmitter release has been correlated with synaptic vesicle exocytosis at discrete sites called “active zones.” Mechanisms for synaptic vesicle membrane retrieval and recycling have been identified by using immunological approaches and correlated with endocytosis via coated pits and coated vesicles. In this review, available ultrastructural, physiological, immunological, and biochemical data have been used to construct an ultrastructural model of neuromuscular synaptic transmission that correlates structure and function at the molecular level.
    Additional Material: 30 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060100204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Freeze-fracture and immunomorphological analysis of spiral ganglion cells (1990)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 15 (1990), S. 155-164 
    Details
    ISSN: 0741-0581
    Keywords: Spiral ganglion ; Freeze-fracture ; Intermediate filaments ; Morphology ; Cytoskeleton ; Membrane ; Labyrinth ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Freeze-fracture analysis of adult spiral ganglion cells of CBA/CBA mice revealed two types of membrane specializations. Most cells (type I) had a smooth surface and were surrounded by Schwann cells. Type II spiral ganglion cells showed numerous membrane specializations with well-delineated indentations similar to those previously found on hair cells adjacent to afferent and efferent nerve endings. Immunomorphological analysis (using well-defined monoclonal antibodies directed against different subclasses of intermediate filament proteins) revealed a unique co-expression of neurofilaments, vimentin and cytokeratins in spiral ganglion cells of 8-to 22-week human fetuses.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060150207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Extrusion of colonic epithelial cells in vitro (1990)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 16 (1990), S. 15-24 
    Details
    ISSN: 0741-0581
    Keywords: Intestine ; Mucosal barrier ; Tight junction ; Freeze-fracture ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Rat colonic mucosae fixed in situ in Ussing chambers provided a model of the extrusion of absorptive enterocytes and less commonly of goblet and enteroendocrine cells. The cells were lost at extrusion zones midway between crypt mouths. Even in mucosae in which the number of extruding cells was large, epithelial continuity was maintained as evaluated morphologically and electrophysiologically. Beneath points of remaining contact between desquamating cells and the epithelial sheet, microfilaments of the terminal web formed band-like structures linking adjacent junctional complexes. Freeze-fracture replicas disclosed extensive macular regions of tight junction strands in the plasma membranes of desquamating cells. Tight junctions between newly neighboring cells were often irregular and often occurred beneath the terminal web region. Dithio-threitol enhanced cell loss and increased basal epithelial conductance, but histological continuity was maintained and the mucosae continued to respond typically to bradykinin. These observations suggest that during the loss of senescent enterocytes, tight junctions are maintained; old junctional elements are lost, and tight junctions are formed between remaining adjacent cells. This model offers a means to study the synthesis and turnover of tight junctions and the maintenance of the colonic epithelial barrier.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060160104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    A review of echinoderm oogenesis (1990)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 16 (1990), S. 93-114 
    Details
    ISSN: 0741-0581
    Keywords: Ultrastructure ; Biochemistry ; Maturation ; Comparative ; Oocytes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: This review of the anatomical, histological, biochemical, and molecular biological literature on echinoderm oogenesis includes the entire developmental history of oocytes; from their inception to the time they become ova. This is done from a comparative perspective, with reference to members of the five extant echinoderm classes; crinoids, holothurians, asteroids, ophiuroids, and echinoids. I describe the anatomy and fine structure of the echinoderm ovary, with emphasis on both the cellular relationships of the germ line cells to the somatic cells of the inner epithelium, and on the neuromuscular systems. I review the literature on the growth of oogonia into fully formed oocytes, including the process of vitellogenesis, presenting an ultrastructural analysis of the organelles and extracellular structures found in fully formed echinoderm oocytes. Echinoderm oocyte maturation is reviewed and a description of the ultrastructural, biochemical and molecular biological changes thought to occur during this process is presented. Finally, I discuss oocyte ovulation, the severing of cellular connections between the oocyte and its surrounding somatic epithelial cells.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060160203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...