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  • 1
    ISSN: 1432-0533
    Keywords: Beta Irradiation ; Initial Brain Lesions ; Histochemistry ; Electron Microscopy ; Mucoproteid Globuli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Köpfe von insgesamt 17 Meerschweinchen beiderlei Geschlechts wurden mit 17 MeV-Betastrahlen homogen bestrahlt. Die Einzeitbestrahlungen erfolgten mit Dosiswerten von 500–5000 R und einer Dosisleistung von 100 R pro Minute. Sämtliche Tiere wurden 24 Std nach der Bestrahlung getötet. Durch PAS- und Astrablau-Reaktionen konnten Globuli, die Mucoproteide und saure Mucopolysaccharide enthalten und vorzugsweise in der weißen Substanz vorkommen, nachgewiesen werden. Die regionäre Verteilung ist von der Dosierung abhängig. Von 2000 R an finden sich in der marknahen Großhirnrinde und Medulla oblongata geschrumpfte und nekrotische Ganglienzellen. Ebenso verhalten sich die Purkinje-Zellen. Diese Veränderungen werden im ultrastrukturellen Bereich bestätigt. Das Ödem findet sich in den Astrocyten; der extracelluläre Raum der grauen Substanz des Cortex ist nicht erweitert.
    Notes: Summary The heads of 17 guinea pigs of both sexes were irradiated homogenously by 7 MeV-beta irradiation. The dosage of the one-time irradiation was 500–5000 R with a dosage of 100 R/minute. All the animals were killed 24 hrs after the irradiation. By means of PAS- and Astrablue reactions globuli containing mucoproteids and acid mucopolysaccharides could be detected mainly in the white matter. Their regional pattern depends on the dosage. Beginning from 2000 R, shrinked and necrotic nerve cells are seen in the deep cerebral cortex and medulla oblongata. Similar lesions are seen in the Purkinje cells. These lesions are confirmed by ultrastructural findings. Edema is found in astrocytes. The extracellular spaces of the cortical gray matter are not enlarged.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 51 (1973), S. 183-190 
    ISSN: 1432-1440
    Keywords: Geriatrics ; clinical chemistry ; Geriatrie ; Klinische Biochemie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Seren von 41 Hundertjährigen wurden vorwiegend mit Hilfe eines Zwölffach-Autoanalyzers und mit der Serumelektrophorese untersucht. Als Vergleichskollektiv dienten die Autoanalyzerwerte von 7900 Patienten der Altersgruppen zwischen 21 und 90 Jahren. Das Ergebnis der statistischen Prüfung läßt sich folgendermaßen zusammenfassen: 1. Ohne Einfluß bleibt das Lebensalter auf die Werte der SGOT. Phosphat, Bilirubin und Gesamteiweiß ändern sich bis zum 80. Lebensjahr kaum und gehen anschließend zurück. Die Durchschnittwerte von Harnsäure und Harnstoff nehmen von der Jugend bis zu den Höchstbetagten stetig zu, die von Calcium und Albumin kontinuierlich ab. Beim Cholesterin, der LDH, der alkalischen Phosphatase und möglicherweise auch beim Blutzucker erreichen die Mittelwerte um das 8. Dezennium ein Maximum und gehen bei den Höchstbetagten wieder zurück. 2. Die rüstigen Hundertjährigen zeigen in fast allen blutserologischen Parametern ein biologisch jüngeres Verhalten als es nach ihrem kalendarischen Alter zu erwarten wäre. So entsprechen die Durchschnittswerte der Vitalitätsgruppe I bei Calcium, Albumin, Gesamteiweiß, Harnsäure, LDH und alkalischer Phosphatase etwa denjenigen der 71–80jährigen. Hinsichtlich des Calcium-, Phosphat- und SGOT-Spiegels lassen sich die vitalen Höchstbetagten wegen der über Jahrzehnte anhaltenden Konstanz der Mittelwerte durchaus mit Personen in mittlerem Alter vergleichen. Gruppe I weist sogar günstigere Blutzuckerwerte als die Gesamtgruppe der 71–80jährigen auf. Lediglich beim Bilirubin (signifikant) und beim Harnstoff (nicht signifikant) zeigen auch die rüstigen Hundertjährigen gegenüber den 71–80jährigen bereits mäßig erniedrigte bzw. erhöhte Werte. Demnach können die rüstigen Langleibigen der Gruppe I als positive Selektion der Gesamtbevölkerung aufgefaßt werden. 3. Die Vitalitätsabnahme von I nach III findet — mit Ausnahme von Cholesterin, LDH und alkalischer Phosphatase — ihr Korrelat in der Verschlechterung der blutchemischen Parameter. 4. Auffallend ist bei den Hundertjährigen ein signifikanter Rückgang des Cholesterins und der alkalischen Phosphatase mit Abnahme der Vitalität. 5. Die siechen Hundertjährigen (Gruppe III) weisen bei Phosphat, Bilirubin, Albumin, Gesamteiweiß, Harnsäure, Harnstoff und SGOT besonders ungünstige Werte auf. Ursächlich können hierfür die zunehmende Organinvolution mit Funktionsinsuffizienz und weiterhin die Auswirkung der Multimorbidität bei diesen Hinfälligen im Stadium der Vita minima verantwortlich gemacht werden.
    Notes: Summary The results of the statistical study can be summarized as follows: 1. The SGOT levels are not influenced by age. Phosphate, bilirubin and total protein are subject to hardly any changes up to age 80, but decrease thereafter. The average values of uric acid and urea (BUN) increase steadily from adolescence until very old age, while those of calcium and albumin fall continuously. The average values of cholesterol, LDH, alkaline phosphatase, and probably also those of blood sugar, reach a maximum around the eight decade and then recede in the very old. 2. In nearly all blood serological parameters vigorous centenarians display a biologically younger behaviour than would be expected in view of their calendar age. Thus the average values for calcium, albumin, total protein, uric acid, LDH and alkaline phosphatase in vitality group I approximate those found in the 71 to 80 age-group. With respect to the calcium, phosphate and SGOT levels, vigorous individuals of very old age show a continuity of the average values which persists over several decades; they can thus be readily compared with middle-aged subjects. In group I the blood sugar values are even more satisfactory than in the total group of the 71 to 80-year-old. In the vigorous centenarians bilirubin (significant) and urea (not significant) are the only parameters showing moderate reductions and increases, respectively, as compared with the 71 to 80 age-group. Hence vigorous long-lived persons can be considered to represent a positive selection from the total population. 3. Except for cholesterol, LDH and alkaline phosphatase, the decrease in vitality from group I to III is correlated with the deterioration of blood chemistry parameters. 4. In the centenarians a striking feature is the significant fall in cholesterol and alkaline phosphatase in association with a decreasing vitality. 5. In invalid centenarians (group III) particularly adverse values are found for phosphate, bilirubin, albumin, total protein, uric acid, urea and SGOT. This would appear to be causally related to increasing organ involution and resulting functional insufficiency, and also to the effects of multiple physical illness which are encountered in these infirm individuals in the stage of minimum life („vita minima“) processes.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 63 (1985), S. 238-240 
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 42 (1964), S. 296-296 
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 51 (1973), S. 151-155 
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 64 (1986), S. 100-100 
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 115 (1993), S. 65-73 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The commensal marine isopod Jaera hopeana Costa, 1853 was reared in the laboratory through 30 generations in the absence of its host, Sphaeroma serratum, to study its development and reproductive behaviour. It was found that adult males take virtually any opportunity to associate with a young conspecific in manca-I stage (first free-living stage) and carry it around in a characteristic position. This male-manca(I) amplexus ends during the manca's first postmarsupial molt (manca-I to manca-II) at an average age of about 9 d after hatching from the marsupium. Entry into amplexus does not alter a manca's molt timing, the duration of the amplexus thus depending exclusively on the manca's age when it joined by a male. Given a choice, males do not prefer manca-I close to molting over those just hatched. With the first postmarsupial molt, long before sexual maturity, female J. hopeana become receptive to mating. Before a female manca is released from amplexus, it is inseminated by its male partner. Sperm transferred to young immature females are stored within special sperm stores until they are needed for fertilization. The male-manca(I) amplexus seems to be a precopula, wherein males wait for their partners to molt and become sexually receptive. Nevertheless, it is inevitable that every second amplexus on average ends unsuccessfully: although manca-I have already been determined irreversibly (and probably genetically) as males and females in equal numbers, adult males are unable to predict which manca-I are potential mates and which are not. Males accept any manca-I as a “precopula” partner, and even when given a choice they do not prefer female over male manca-I. From the manca-II stage onward, females are continuously receptive to mating for the rest of their life, and mating can occur immediately upon contact of the partners without any significant investment in energy and time (“en passant” copulation).
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-0649
    Keywords: PACS: 02; 81.60; 87
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 55 (1992), S. 41-48 
    ISSN: 1432-0630
    Keywords: 78.20 ; 85.60 ; 78.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Polymer lightguides of PMMA doped with the azo dyes methyl-red and N, N-dihexyl-4-amino-4'-nitro-azobenzene (DHANA) are investigated with respect to their opto-optical properties. The trans-cis photoisomerisation of the dyes leads to reversible polarization-dependent optically induced refractive index changes. The index changes are anisotropic. Birefringence is measured using index matched lightguides. The changes with respect to each polarization are determined by leaky mode spectroscopy and by using a half-integrated interferometer. These changes are intensity dependent and, with a suitable geometry, bistability at low intensities (3 mW/mm3) can be obtained.
    Type of Medium: Electronic Resource
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