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  • 1976  (2)
  • Biochemistry
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 169 (1976), S. 193-209 
    ISSN: 1432-0878
    Keywords: Planaria ; Starvation ; Fine structure ; Biochemistry ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Employing a combination of microscopical, biochemical and autoradiographic techniques, the primary effects of starvation on adult Polycelis tenuis have been studied. Over a five week period of starvation there is on average a 32% decrease in the size of the organism. This decrease is contributed to by a reduction in mitosis and an increase in cell shrinkage autolysis and death. During starvation (following a sharp rise in RNA synthesis) there is a distinct sequence of events; four peaks of acid phosphatase activity can be resolved. The first is associated with the immediate response of the gastrodermis to feeding; the second (after 6 to 7 days) with increased autophagy and dedifferentiation in the gland cells and with muscle lysis; the third peak (after 14 to 15 days) is contributed to largely by the lysis of cells in the gut and the fourth peak (after 25 to 26 days) is caused by an extensive lysis of the reproductive system. Fine structural changes involving increased intracellular vacuolation, autophagy, crinophagy, atrophy of muscle, increased intercellular space and loss of basement membrane matrix have been related to changes in enzyme pattern. Nerve cells appear unchanged throughout the first five weeks of starvation. Pigment and gland cells loose their characteristic granules, dedifferentiate and become morphologically similar to the undifferentiated neoblasts. Dedifferentiation and the mechanisms involved in the survival of starvation are discussed.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 212 (1976), S. 253-262 
    ISSN: 1434-4726
    Keywords: Hydrops ; Membranous labyrinth ; Menière's disease ; Biochemistry ; Fluid physiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der endolymphatische Hydrops vorn nicht fortschreitenden Typ entsteht nach einmaligem Trauma oder kurzzeitiger Intoxikation. Obwohl ein bleibender Verlust der Sinnesfunktion eintreten kann, fehlen vestibuläre Symptome. Der endolymphatische Hydrops vom fortschreitenden Typ scheint durch ständige Störung der Endolymphresorption zu entstehen und wird vor allem durch Erkrankungen des Saccus endolymphaticus verursacht. Diese Form findet sich bei der Menièreschen Erkrankung, der syphilitischen Labyrinthitis und beim „Delayed hydrops syndrome“. Neben verschiedengradigen Hörstö rungen findet man hier anfallsartigen Schwindel und manchmal das Henne bertsche Zeichen. Histologische Untersuchungen lassen vermuten, daß die Schwindelanfälle durch Kaliumintoxikation nach Rupturen im membranösen Labyrinth verursacht sind, während das Hennebertsche Zeichen durch eine Fibröse des Vestibulums bedingt wird.
    Notes: Summary Endolymphatic hydrops of the nonprogressive type occurs in response to a single traumatic or toxic insult of limited duration and although it may result in permanent deficits in sensorineural function, there is total subsidence of vestibular symptoms. Endolymphatic hydrops of the progressive type, on the other hand, appears to be the result of permanent impairment of endolymph resorption and is caused principally by disorders of the endolymphatic sac. It occurs in Menière's disease, syphilitic labyrinthitis and the delayed hydrops syndrome. In addition to deafness of varying extent, it is characterized by episodic vertigo and sometimes by Hennebert's sign. Histological studies suggest that the acute vertiginous episodes are caused by potassium intoxication following ruptures of the membranous labyrinth and that Hennebert's sign is caused by vestibular fibrosis.
    Type of Medium: Electronic Resource
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