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  • Polymer and Materials Science  (4)
  • Electron microscopic autoradiography  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 113 (1971), S. 441-449 
    ISSN: 1432-0878
    Keywords: Noradrenergic nerves ; Terminals ; Uptake of 5-hydroxytryptamine ; Electron microscopic autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The uptake and distribution of radioactivity in vascular adrenergic nerves in the mouse pancreas following the injection of tritiated 5-hydroxytryptophan was studied by means of electron microscopic autoradiography. Autoradiographic silver grains were found selectively accumulated over axonal profiles. Quantitative analysis revealed a characteristic intraneuronal distribution of the silver grains, most of which probably represent 5-hydroxytryptamine formed by decarboxylation from the labeled precursor. Thus, the grain density over adrenergic nerve terminals, containing a mixed population of vesicles and granules, was about 5 times higher than the grain density recorded over non-terminal axonal parts and at least 20 times higher than the grain density found over surrounding adventitial tissue and smooth muscle cells. This was interpreted as an evidence that 5-hydroxytryptamine was taken up and stored in adrenergic terminals.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 206 (1980), S. 73-81 
    ISSN: 1432-0878
    Keywords: Exocrine pancreas (mouse) ; Electron microscopic autoradiography ; Microtubules ; Protein transport ; Vinblastine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of vinblastine on the intracellular transport of newly synthesized protein in the mouse exocrine pancreas in vivo was studied by electron microscopic autoradiography after administration of 3H-leucine. Vinblastine (1.1 μmole/mouse; i.v. injection) was in general given 1 h before radioleucine and 2–4 h before fixation of the pancreas by perfusion with glutaraldehyde. Vinblastine causes the disappearance of microtubules, mainly present in controls in the apical portion of the acinar cell. After injection of vinblastine, zymogen granules form clusters located throughout the cell but often associated with Golgi areas. The latter are enlarged mainly due to the accumulation of small vesicles. In addition, Golgi areas are displaced, most often in an apical direction. Electron microscopic autoradiography demonstrated that vinblastine delays the appearance of labeled protein in zymogen granules; even 2 h after injection of radioleucine the majority of silver grains is located over the rough endoplasmic reticulum while very few grains are related to zymogen granules. This finding might be related to the structural changes of the Golgi areas observed. Although intracellular migration of protein is retarded, zymogen granules are formed. However, many of the labeled granules are found in peculiar locations, often distant from the acinar lumen. The present study suggests that vinblastine, possibly due to its effect on microtubules, influences both the formation and the translocation of zymogen granules.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 193 (1978), S. 73-85 
    ISSN: 1432-0878
    Keywords: Insulin release ; Adrenergic receptors ; Stereospecificity ; Adrenergic innervation ; Electron microscopic autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An investigation of the stereospecificity of β-adrenergic insulin release, its relation to α-adrenergic blockade and the adrenergic innervation of the pancreatic islets was performed in the mouse. It was observed that in vivo β-adrenergic stimulation of insulin release by isopropylnoradrenaline was stereospecific for the L-stereoisomer and selectively blocked by the L-isomer of the β-adrenergic antagonist L-propranolol. D-propranolol had no effect. Pretreatment of mice with a dose of D-isopropylnoradrenaline devoid of insulin releasing activity, slightly increased the subsequent insulin response to a halfmaximal dose of L-isopropylnoradrenaline. Basal insulin secretion was blocked by L-propranolol (β-adrenergic blockade) and increased by phentolamine (α-adrenergic blockade). A β-blocked insulin response to L-isopropyl-noradrenaline could be overcome by α-adrenergic blockade depending on the dose of the β-agonist, suggesting a close association between the adrenergic receptors. The adrenergic innervation of the islet cells was studied by electron microscopic autoradiography after injection of 3H-L-noradrenaline. It was observed that labelled adrenergic nerve terminals were associated with both A1(D-), A2 and B-cells. The nerves were mainly distributed in the periphery of the islets either as single axons or as bundles. The majority of the terminals were associated with A2-cells, the most frequent cell type in the islet periphery. However, in all islets examined terminals were found close to B-cells. Adrenergic terminals often caused indentations in the contour of an islet cell and were separated from the islet cell membrane only by a narrow intercellular space, about 20 nm in width. It is concluded that the islet cells of the mouse are equipped with the morphological substrate for direct adrenergic regulation. Further it is suggested that the B-cell is supplied with L-stereospecific β-adrenergic receptors and that the α- and β-adrenergic receptors are at least partially interrelated.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 41 (1998), S. 574-583 
    ISSN: 0021-9304
    Keywords: artificial implants ; calcium phosphates ; titanium ; osteointegration ; arthroplasty ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The early healing phase of hard tissue implants is important to their long-term success. Problems during this phase can result in a so-called primary biological failure. In 24 New Zealand white rabbits, the healing in cortical bone of noncoated TiAlV and cpTi cylinders and of TiAlV cylinders plasma-spray-coated with hydroxyapatite (HA) or fluorapatite (FA) was investigated histologically and histomorphometrically after 3, 7, 14, and 28 days. Histomorphometry consisted of bone contact measurements and the use of a new semi quantitative scoring system that discriminated various tissues in contact with the implant. The results demonstrated that the most important parameter in initial implant healing is the bone itself and not the characteristic of the implanted material. For all implants, healing was characterized by a sequence of hematoma formation, bone resorption, and new bone formation where the initial press-fit situation revealed more bone-implant contact than after 7 and 14 days. There were only minor differences between the implant types: the new bone formation directly on the implant surface was qualitatively histologically superior to the CaP-coated implants, but this could be confirmed with the scoring method only for the HA-coated implants. It is concluded that initial press-fit fixation in cortical bone is not an end situation; rather, what happens is that as a result of interface remodeling, early postoperatively implant integration in the bone will decrease temporarily prior to a subsequent phase of new bone formation. © 1998 John Wiley & Sons, Inc. J. Biomed Mater Res, 41, 574-583, 1998.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 24 (1990), S. 847-860 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Ion implantation modifies the surface properties of different materials. We have compared the biological properties of titanium implanted with nitrogen with those of pure titanium. Implants were inserted in the abdominal wall of rats. The implants with surrounding tissue were excised after 1 and 6 weeks, and embedded in epoxy resin. The bulk metal was removed electrochemically and the tissue cut for light and electron microscopy. Using this technique the implant surface, formed by a thin oxide layer, remains and appears in sections as a dense line. After 1 week both types of implants were surrounded by a fluid space containing proteins and scattered macrophages but few polymorphonuclear granulocytes. The fluid space was wider around ionimplanted titanium (52 ± 22 μm) than around pure titanium implants (15 ± 3 μm). After 6 weeks the fluid space had largely disappeared around both type of implants. Around pure titanium implants macrophages and fibroblasts, quantified in 1-μm-thick sections in the light microscope, were present in about the same concentration in the inner tissue zone (within 25 μm from the implant surface). Around ion-implanted titanium macrophages predominated in the inner zone and multinuclear giant cells were present in almost all sections. Around both type of implants fibroblasts increased and macrophages decreased with increasing distance from the surface. In the electron microscope macrophages close to the surface of pure titanium were of small size and had an ultrastructure indicating a low activity. Macrophages close to ion-implanted titanium were large and had an active appearance as indicated by the presence of large amounts of endoplasmic reticulum and large Golgi areas in the cytoplasm. Our observations indicate that modification of the surface properties of titanium implants by ion implantation changes the biological properties.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 18 (1992), S. 381-386 
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A superlattice sample consisting of 200 alternating 5 nm layers of GaAs and Al0.45Ga0.55As was analyzed to explore some of the factors affecting depth resolution in rotational depth profiling by AES, including coincidence of sample rotation and probe beam axes, stability of analysis position and probe beam current density. Because of the periodic nature of the layers involved, it was possible to detect very small (〈 2 nm) changes in surface topography. A mathematical model is proposed which explains the unusual features observed in the AES profile.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 16 (1990), S. 567-568 
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Type of Medium: Electronic Resource
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