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  • 1
    ISSN: 1433-8580
    Keywords: Kidney-transplantation ; Xenotransplantation ; Closely related species ; Delayed hyperacute rejection ; Nierentransplantation ; Xenotransplantation ; Nah verwandtes System ; Verzögert hyperakute Abstoßung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Um das Verhalten vascularisierter Xenotransplantate zwischen Tieren enger zoologischer Verwandtschaft zu untersuchen, wurden Katzennieren „en bloc“ auf Hunde transplantiert. In diesem System zeigte sich, mit einer Funktionsdauer von 15–24 Std, der Typ einer verzögert hyperakuten Abstoßung. Der Abfall des Komplements im peripheren Blut und das Auftreten von Katzenprotein im Urin schon während der ersten Stunden deutet auf einen früheren Beginn dieser Reaktion hin, während die endgültige Zerstörung des Transplantates durch unspezifische, jedoch von der Antigen-Antikörper-Reaktion gestartete Mechanismen bedingt zu sein scheint. Den Empfängern dieser Ersttransplantate wurden 3 Wochen später mit einer Ex vivo-Hämoperfusion eine zweite Katzenniere angeschlossen. Innerhalb von 15–20 min waren diese Nieren unter dem Bild einer typischen hyperakuten Abstoßung zerstört.
    Notes: Summary To study the survival time of kidney-transplants in closely related species cat kidneys were transplanted to the iliac vessels of mongrel dogs by an “en bloc” method. A type of delayed hyperacute rejection was observed. The function time of the transplant kidneys ranged from 15 to 24 hrs. The decrease of complement activity and the appearance of cat-tissue protein in serum and urine samples show that the rejection began at an early stage. Since the antigen-antibody reaction seems to be finished after 6 hrs, indicated by an increase of complementactivity, the final loss of function may be effected by an unspecific reaction. Recipients survived after removal of the transplant and got a second kidney graft 3 weeks after the first set. These kidneys were rejected within 15–20 min with the sign of typical hyperacute rejection.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 1 (1973), S. 69-71 
    ISSN: 1432-0630
    Keywords: Absorption ; Dielectric coatings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The absorption of optical coatings can be measured by the method described with an accuracy of 0.001%. The radiation absorbed by the optical coating causes a change in the temperature of the coating and the substrate. The temperature change is measured by means of a thin-film resistance thermometer deposited on the substrate. The method was tested for laser reflectors at 1060 nm with a laser as a light source.
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  • 3
    ISSN: 1433-8580
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 4
    ISSN: 1433-8580
    Keywords: Hemoperfusion ; Xenogeneic rejection ; Preformed natural antibodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung E vivo-Hämoperfusion von Katzennieren durch unbehandelte Hunde wurde ausgeführt. Dieses Modell erlaubt Blut- und Urinanalysen zu jeder gewünschten Zeit und besitzt so einen gewissen methodischen Vorteil gegenüber der Transplantation. Die xenogenen Nieren wurden bis zu 15 Std funktionstüchtig erhalten. Im Gegensatz zu xenogenen Transplantationen bei Tieren innerhalb einer zoologischen Familie, bei denen celluläre Abstoßungsreaktionen auftreten, scheint in diesem System von Tieren, die einer gemeinsamen Ordnung angehören, der humorale Typ der Abstoßungsreaktion vorzuherrschen. Speciesspezifische, jedoch nicht organspezifische präformierte natürliche Antikörper setzen eine Folge von humoralen und cellulären Mechanismen in Gang, die zu einer fortschreitenden Zerstörung des Organs führen. Im Urin und Serum gemessene Parameter zeigen, daß eine hyperakute xenogene Abstoßungsreaktion, die im nah verwandten Speciessystem auftritt, verglichen mit der HXAR bei entfernt verwandten Species abgeschwächt und verzögert ist und daher unterschieden werden sollte.
    Notes: Summary E-vivo hemoperfusions of cat kidneys by untreated dogs were performed. Because analyses of blood and urine can be done at any time, this model has the methodical advantage above transplantation. The function time of the xenogeneic cat kidneys ranged from 10–15 hrs. In contrast to xenotransplants of closely related animals within a zoological family, which are destroyed by cellular actions, the rejection of grafts of nearly related species within a zoological order seems to be governed by humoral mechanisms. Speciesspecific but not organspecific PNAB trigger humoral and cellular factors, that lead to progressiv organ destruction. Urine and serum parameters show, that the HXR in nearly related species, compared to HXR in widely divergent species, is delayed and weakened and should therefore be distinguished.
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  • 5
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A scintillation counter telescope has been flown in the upper atmosphere at2.4g/cm2 from Bergen/Lüneburger Heide for the measurement of electrons and photons of the secondary cosmic radiation. The aim was to get the differential energy spectra of secondary photons in an energy range from 1 to 44 MeV and of secondary and return albedo electrons from 2 to 35 MeV for three different zenith angles (0 °, 90 ° and 180 °). The received photon spectrum is in good agreement to the results of other authors as well to lower as to higher energies. It has been shown, that the spectrum has a great anisotropy with a maximum of intensity around the horizon. The main reason therefore is the atmospheric deepness in the different directions. In this energy range we have found that the Bremsstrahlung of the return albedo electrons is the main reason for the photon flux and secondly the π0-decay. The measured electron spectra don't show any significant difference relative to the three zenith angles. These secondary electrons are produced isotropically in the upper atmosphere and they consist of a mixture of secondary and return albedo electrons.
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 3 (1971), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The published chromosome numbers for 208 temperate and tropical freshwater fishes have been compiled in alphabetical order within the families. This facilitates the work for ichthyologists interested in the karyotype(s) of a particular species, genus or family as well as giving an overall account of the basic chromosome numbers and karyological trends in fishes.
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  • 7
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— A new combined ion-exchange and thin-layer-chromatographic procedure is described which separates and measures quantitatively, after intraventricular injection of [3H]dopamine (DA), the rat brain content of labelled noradrenaline (NA) and the following labelled noradrenaline metabolites: free 3-methoxy-4-hydroxyphenylethyleneglycol (MOPEG), conjugated MOPEG, free plus conjugated dihydroxyphenylethyleneglycol (DOPEG), vanillic mandelic acid (VMA) and normetanephrine (NM). Labelled dopamine and its metabolites were also measured. The time-course study performed from 5 min to 24 h after [3H]DA showed that MOPEG and DOPEG, mainly as conjugates, are major NA metabolites whereas VMA is a very insignificant NA metabolite in the rat brain. A very rapid initial increase of [3H]NM, free MOPEG and conjugated MOPEG was found during the time interval where the [3H]NA biosynthesis is very high (0–15 min). This combined with the finding that these metabolites stabilize at lower levels during the [3H]NA ‘storage phase’ (9–24 h) provides a strong indication that newly synthesized NA preferentially is metabolized. Our measurements of endogenous NA, free MOPEG and conjugated MOPEG provide additional support. The injections of various decreasing doses of [3H]DA (3·08–0·0010 μg) showed that the proportions of total [3H]MOPEG and total [3H]DOPEG to [3H]NA were constant after all [3H]DA doses investigated. This finding indicates that the [3H]NA synthesized in situ behaves as a tracer, even after injections of non-tracer doses of [3H]DA. The results seem thus to indicate that the present technique provides a powerful tool for the investigations on central noradrenaline metabolism.
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  • 8
    ISSN: 1432-2072
    Keywords: Amphetamines ; Apomorphine ; Clonidine ; Body Temperature ; 5-Hydroxytryptamine Metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Amphetamine and various amphetamine derivatives, phenmetrazine, pipradrol, methylphenidate and NCA can increase the concentration of 5-HIAA in the rat brain without changing that of 5-HT. Metamphetamine produced a decrease in 5-HT and no effect on 5-HIAA whereas p-hydroxyamphetamine produced no effects on 5-HT and 5-HIAA. The experiments performed at different environmental temperatures (12–14
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  • 9
    ISSN: 1432-1912
    Keywords: Protriptyline ; Noradrenaline Biosynthesis ; 3H-l-Dopa ; 3H-l-Tyrosine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 3H-l-Dopa was given intraperitoneally, after a peripheral decarboxylase inhibitor Ro 4-4602 (50 mg/kg), to male Wistar rats and the effect of protriptyline pretreatment (10 mg/kg, 30 min) on the formation and metabolism of the brain 3H-catecholamines, dopamine and noradrenaline and all their metabolites was investigated. Protriptyline produced a strong decrease of labelled noradrenaline and its metabolites normetanephrine, free and conjugated 3-methoxy-4-hydroxyphenyl-eneglycol and 3,4-dihydroxyphenyleneglycol 60 and 120 min after 3H-l-Dopa. 3H-noradrenaline was also decreased 30 and 45 min after 3H-l-Dopa. In rats and mice the pretreatment with protriptyline (10 mg/kg, 30 min) induced also a significant decrease in brain 3H-noradrenaline but not 3H-dopamine synthesized from 3H-l-tyrosine. Protriptyline (10 mg/kg) produced no effect on endogenous dopamine and noradrenaline in the rat or mouse brain. The present findings strongly indicate that the acute treatment with protriptyline inhibits the 3H-noradrenaline formation from 3H-l-Dopa. This effect seems most likely to be related to an interaction of protriptyline with the precursor(s) 3H-l-Dopa or 3H-dopamine at sites of 3H-noradrenaline biosynthesis.
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  • 10
    ISSN: 1435-1803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Mechanismen, die nach einer fortschreitenden Koronarokklusion (Ameroid-Methode) zur Kollateralentwicklung führen, wurden an Hunden untersucht. Mit Hilfe der Regelungstheorie und quantitativer experimenteller Daten wurde das Koronarsystem analysiert. Unter anderen Varianten wurden der periphere Koronardruck, die periphere Koronardurchblutung, Koronarreserve, Kollateralwiderstand, der periphere Koronarwiderstand, Sauerstoffverfügbarkeit und-verbrauch in Betracht gezogen. In dieser Analyse wurden die folgenden Möglichkeiten in Betracht genommen: 1. ob Ischämie der einzige Reiz zur Kollateralenbildung sein könnte; 2. die peripheren Koronargefäße autoregulieren und der periphere Koronarwiderstand während Ischämie steigt; 3. Autoregulation besteht, der periphere Widerstand sinkt auf ein Minimum ab, aber steigt nicht wieder unter dem Einfluß der Ischämie; 4. der periphere Widerstand bleibt konstant. Die Resultate erwiesen, daß weder Ischämie allein noch ein Druckgefälle allein für die Kollateralenbildung verantwortlich sein können. Die Hypothese, daß Ischämie das Kollateralenwachstum veranlaßt, dieses Wachstum aber von hämodynamischen Faktoren weiter erhalten wird, wurde vorgelegt.
    Notes: Summary The mechanisms for development of collaterals following a gradual occlusion (Ameroid technique) of one the coronary arteries in the dog were investigated. A control systems approach, based on quantitative experimental data, was utilized. The peripheral coronary pressure, peripheral coronary flow, coronary reserve flow, collateral resistance, peripheral coronary resistance, oxygen availability and demand were among the parameters studied. These variables were followed through the preocclusion phase, occlusion phase, ischemic phase, and post-ischemic phase of a gradual coronary constriction. The simulation studies were examined for the following basic assumptions: 1) ischemia is the sole stimulus for collateral development, 2) the peripheral coronary vasculature exhibits autoregulation and the peripheral coronary resistance increases during ischemia, 3) autoregulation occurs but during ischemia the peripheral vasculature remains maximally dilated without increase in resistance, and 4) the peripheral coronary vasculature is non-autoregulatory. It was concluded that neither ischemia nor a pressure differential can solely account for collateral development It is believed that ischemia begins the collateral growth process and it is sustained by the pressure differential (or some manifestation thereof) during the post-ischemic phase. Assumption 2 is most consistent with both physiological and clinical data. The autoregulatory capacity of the peripheral coronary bed allows a constriction of 76% before the resting coronary flow is impaired.
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