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  • 1970-1974  (3)
  • Node of Ranvier  (2)
  • Biliodigestive Fistulae  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Effect of aconitine on the sodium permeability of the node of ranvier (1974)
    Springer
    Pflügers Archiv 349 (1974), S. 133-148 
    Details
    ISSN: 1432-2013
    Keywords: Node of Ranvier ; Sodium Permeability ; Aconitine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of aconitine (10−5–10−6 g/ml) on membrane potentials and membrane currents of myelinated nerve fibres of Xenopus laevis was investigated. The following observations were made: a) Current clamp conditions: Slow depolarization (10–15 mV), decrease of amplitude and maximum rate of rise of action potential, finally inexcitability. With inward current pulses ‘hyperpolarizing responses’ could be elicited at membrane potentials more negative than the resting potential (E r ). Neither spontaneous activity nor repetitive responses to electrical stimuli were observed. No effects of aconitine were found in Na-free solutions or in the presence of tetrodotoxin. b) Voltage clamp conditions: Development of steady inward current at normal resting potential due to formation of a non-inactivating sodium permeability; heavily poisoned nodes therefore exhibit an N-shaped steady-state current voltage relation with negative slope at membrane potentials more negative thanE r . These non-inactivating sodium channels open more slowly than normal sodium channels, and can only be closed by hyperpolarizing the membrane by about 50 mV. The majority of sodium channels have almost normalτ m; theirm ∞ andh ∞-V relations are shifted by 10–15 mV towardsE r . It is concluded that these changes of the sodium permeability account for the changes of electrical activity observed after treatment with aconitine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00586624
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  • 2
    Electronic Resource
    Electronic Resource
    Influence of calcium ions on the ionic currents of nodes of Ranvier treated with scorpion venom (1972)
    Springer
    Pflügers Archiv 333 (1972), S. 51-61 
    Details
    ISSN: 1432-2013
    Keywords: Node of Ranvier ; Ionic Currents ; Scorpion Venom ; Calcium Ions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Voltage clamp experiments were done on myelinated nerve fibres of Xenopus laevis to study the effect of calcium on the ionic currents of the nodal membrane treated with scorpion venom. Increasing the calcium concentration of the medium from 1.8 to 7.2 mM produced the following changes of the sodium and potassium permeabilities,P Na andP K: a) The incomplete sodium inactivation, which is typical for nodes of Ranvier treated with scorpion venom, is abolished. The curves relatingm ∞ and τ m to membrane potential are shifted by 8–10 mV towards larger depolarizations.P Na and the time constants of the fast and slow components of the sodium inactivation remain practically unchanged. b) The maximum potassium permeability,P K, which is reduced by scorpion venom to 45% of the value observed in the normal node, increases to 68% by addition of calcium ions; τ n is unchanged. These effects of calcium ions on the ionic permeabilities explain the shortening of the extremely prolonged action potential and the inhibition of spontaneous activity observed in nodes of Ranvier poisoned with scorpion venom.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00586041
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    138. Biliodigestive Fisteln (1974)
    Springer
    Langenbeck's archives of surgery 337 (1974), S. 817-818 
    Details
    ISSN: 1435-2451
    Keywords: Biliodigestive Fistulae ; Biliodigestive Fisteln
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In den letzten 10 Jahren wurden 65 Patienten wegen einer biliodigestiven Fistel operiert. In den meisten Fällen bestand eine Verbindung mit dem Duodenum. Die häufigste Ursache war eine Cholelithiasis. In über der Hälfte der Fälle mußte neben einer Cholecystektomie der Choledochus wegen einer Choledocholithiasis oder krankhaften Papillenveränderungen revidiert werden. Als Therapie der Wahl ist eine Sanierung der erkrankten Gallenblase und der Gallenwege mit Verschluß der Fistelöffnung im Magen-Darm-Trakt anzustreben, wobei der intraoperativen Cholangiographie und Manometrie eine besondere Bedeutung zukommt.
    Notes: Summary In the last ten years 65 patients have been operated on for biliodigestive fistulae. In most cases connections to the duodenum had been detected. The most frequent cause was cholelithiasis. Choledocholithiasis or a disease of the papilla made revision of the choledochus necessary as well as cholecystectomy in more than half these cases. The only true therapy is cholecystectomy and revision of the choledochus with closing of the fistula opening in the stomach and the gut. Intraoperative cholangiography and manometry are important.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01278770
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    Paper (German National Licenses)
    Fulltext
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