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  • 1
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 331-337 (May 2000), p. 889-900 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 331-337 (May 2000), p. 1151-1156 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract On guinea-pig heart we investigated whether cyclic AMP serves as a messenger for H1- and/or H2-mediated responses to histamine. (1) On papillary muscle histamine elicited positive inotropic responses which were antagonized by burimamide but not by promethazine. The stimulation of H2-receptors was not only associated with an increase in contractility but also with an increase in cAMP. As shown by the time course of effects for 10−5 M histamine, the maximal increase in cAMP preceded the maximum in contractility. The mechanical and biochemical responses to histamine were potentiated by the phosphodiesterase inhibitor papaverine, but antagonized by burimamide. (2) On the left guinea-pig atrium containing H1-receptors the inotropic response to histamine (10−5 M) was not accompanied by increases in cAMP at stimulation frequencies of 0.5 and 2 Hz, respectively. In addition, in the presence of papaverine (3×10−5 M) no change in the cyclic AMP level occurred after application of histamine. Papaverine by itself, however, concomitantly increased contractility and cyclic AMP at a stimulation frequency of 0.5 Hz. In contrast, at 2 Hz papaverine increased only cAMP leaving the contractility unchanged. At this frequency the well-known Ca2+-antagonistic effect comes into prominence, thus masking the positive inotropic effect atributable to the inhibition of the phosphodiesterase. (3) On the right guinea-pig atrium the mediation of the positive charonotropic response to histamine by H2-receptors which is partly involved in the inotropic effect via the frequency-force relationship does not lead to a concomitant increase in cAMP. Also, in the presence of papaverine, histamine had no influence on the cAMP. However, papaverine potentiated the cardioacceleration produced by histamine. Although it is very likely that the cAMP in the sinus node rises, we were not able to detect an increase in cAMP in the whole atrial tissue. From the present results the conclusion can be drawn that the mediation of the inotropic effect due to stimulation of H2-receptors by histamine is associated with an increase of cyclic AMP, whereas that of H1-receptors is not. The view that cAMP may be the second messenger in the chronotropic action of histamine needs further elucidation by experiments on sino-atrial cells.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 116 (1978), S. 452-464 
    ISSN: 1420-9136
    Keywords: Trace gases ; Atmosphere ; Sources and Sinks ; Methane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract In 1972 average mixing ratio of methane in the troposphere was 1.41 ppm and 1.3 ppmv for the northern and southern hemisphere, respectively, which corresponds to a total amount of 4×1015 g of CH4 present in the atmosphere. Most is of recent biologic origin.14C analyses show that no more than 20 percent is released by fossil sources. The various ecosystems producing CH4 are discussed and the total annual production is estimated to lie between 5.5×1014 g/yr and 11×1014 g/yr. The corresponding turnover times for atmospheric CH4 range from 4 to 7 yrs. The destruction of CH4 takes place mainly in the troposphere, most probably through the reaction of CH4 + OH ↠ CH3 + H2O. About 10 percent of the CH4 is destroyed in the stratosphere. The CH4 cycle contributes on the order of 1 percent to the atmospheric carbon cycle.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1420-9136
    Keywords: Electron paramagnetic resonance ; Free radicals ; Matrix isolation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract With some special adaptations the technique of matrix isolation followed by detection through electron paramagnetic resonance (EPR) can also be used for the measurement of atmospheric radical concentrations. A light weight cryogenic sampling device has been constructed. It uses condensation of atmospheric CO2 or H2O at 77 K for matrix formation and trapping of the radicals. The sampler has been flown on a balloon for stratospheric sampling. First data on stratospheric, HO2 and NO2 at 32 km altitude have been obtained on a flight on 8 August 1976 and will be reported.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 50 (1972), S. 797-798 
    ISSN: 1432-1440
    Keywords: Folic acid ; acute renal failure ; macula densa ; peripheral plasma renin activity ; hemorrhage ; Folsäure ; akutes Nierenversagen ; Macula densa ; periphere Plasma-Reninaktivität ; Hämorrhagie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die periphere Plasma-Reninaktivität war bei Ratten mit akutem Nierenversagen, das durch eine einmalige i.v. Injektion von Folsäure (250 mg/kg KG, gelöst in 0,3 M NaHCO3) erzeugt worden war, während der ersten 6 Std normal und nach 24 Std und 4 Tagen harabgesetzt. Hämorrhagie verursachte jedoch am 4. Tag nach Folsäuregabe einen starken Anstieg der Plasma-Reninaktivität. Für eine Beteiligung des Renins an der Entwicklung des folsäurebedingten funktionellen und morphologischen Nierenschadens ergab sich kein Anhalt.
    Notes: Summary Peripheral plasma renin activity in acute renal failure induced in rats by a single i.v. injection of folic acid (250 mg/kg b. w., dissolved in 0.3 M NaHCO3) remained normal during the first 6 hours and fell to low levels 24 hours and 4 days following the injection. Bleeding, however, induced a considerable increase of plasma renin activity on the 4th day after folate injection. There was no evidence of a participation of renin in the development of the functional and morphological renal disturbances produced by folic acid.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-1750
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Durch die intakte tracheobronchiale Wand der isolierten Trachea-Lungenweg-Präparate von gesunden Ratten und Ratten mit Bronchitis wurden die Flimmerbewegung und der Sekrettransport direkt untersucht. 2. Auf dem tracheobronchialen Epithel der jungen, gesunden Ratte wurde der Schleim in Form von Flocken und Flockenverbänden (Plaques) transportiert. 3. Die Geschwindigkeit des Schleimtransportes stieg mit zunehmendem Abstand von den Lungenbläschen an. Sie war in der Trachea etwa 20–40mal größer als in den präterminalen Bronchiolen. 4. Bei Bronchitis fanden sich herdförmige Wandverdickungen des tracheobronchialen Baumes. Histologische Untersuchungen dieser Regionen ergaben charakteristische Veränderungen der Bronchialwand. 5. Der Flimmermechanismus war in diesen bronchitischen Herden gestört: a) Bei einer Anzahl Flimmerzellen war die Cilienbewegung strudelnd oder pendelnd ohne Differenzierung der Schlagphasen. b) Unmittelbar benachbarte Flimmerzellen führten voneinander unabhängige Cilienbewegungen aus. c) Der effektive Flimmerschlag war bei einer großen Zahl von Flimmerzellen nach caudal gerichtet. 6. Die Schleimelimination war in diesen Regionen mit gestörtem Flimmermechanismus stark beeinträchtigt.
    Notes: Abstract 1. By means of an incident light microscope, the mucociliary activity was studied through the intact tracheobronchial wall of healthy and bronchitic rats in vitro. 2. In the tracheobronchial tree of young healthy rats, mucus was transported in the form of individual homogeneous flakes or as aggregations of several of these flakes (plaques). 3. The average velocity of mucus transport increased progressively with increasing distance from the alveoli, and was found to be 20–40 times greater in the trachea than in the terminal bronchioles. 4. In bronchitic rats the pathological alterations of the bronchial wall were generally confined to patchy areas, and the intervening mucosa was normal. 5. Specific abnormalities of ciliary mechanism were observed in these patchy areas: numerous ciliated cells with modified beating type or reversed effective stroke of the cilia were present, and in several groups of ciliated cells the pluricellular coordination was impaired. 6. Considering the pathogenesis of chronic bronchitis, these results suggest that the primary events might be deficiencies in ciliary function: the impaired clearance function of the ciliated epithelium would facilitate the penetration of bacteria and other foreign bodies and give rise to classical inflammatory processes.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Lung 144 (1971), S. 253-265 
    ISSN: 1432-1750
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Zur Untersuchung bronchomotorischer Vorgänge in allen Abschnitten des Atemweges von der Trachea bis zu den terminalen Bronchiolen wurde eine Methode entwickelt. 2. Verschiedene Atemwegsabschnitte zeigten deutlich unterschiedliche Reaktionen gegenüber bronchoconstrictorischen Stoffen und Temperaturveränderungen. 3. Die terminalen Bronchiolen und die ihnen vorgeschalteten Atemwege reagieren bei Unterschreiten einer kritischen Lumenweite mit totalem Verschluß der Lichtung (Bronchiolen-Kollaps). 4. Isoproterenol hemmte den Effekt des Serotonins, aber nicht den des Acetylcholins. Acetylcholin-Bronchoconstriction wurde sehr effektiv durch Atropin aufgehoben. 5. Die Existenz β-adrenerger Receptoren an der Bronchialmuskulatur der Ratte wurde nachgewiesen.
    Notes: Abstract 1. The authors present a method for the study of the dynamics of various portions of the trachebronchial tree. 2. Various types of bronchi showed different responses to physical and pharmacological stimuli. 3. The terminal and preterminal bronchioles closed abruptly as soon as their diameters were reduced to a critical value (bronchiolar collapse). 4. Isoproterenol inhibited the effect of serotonin, but not that of acetylcholine. Acetylcholine was effectively antagonized by atropine. 5. Evidence was presented for the existence of β-adrenergic receptors in the bronchial tree of rats.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Der Hautarzt 47 (1996), S. 763-766 
    ISSN: 1432-1173
    Keywords: Schlüsselwörter Malakoplakie ; Kutane Manifestation ; Michaelis-Gutmann-Körperchen ; Psoriasis vulgaris ; Key words Malakoplakia ; Cutaneous manifestation ; Michaelis-Gutmann-bodies ; Psoriasis vulgaris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary A 58 year old patient suffering from psoriasis vulgaris had typical erythematous, scaly plaques for 20 years. In addition, an erosive, therapy-resistant plaque was found in the perianal region. A biopsy was taken to exclude malignancy; it showed intracytoplasmic Michaelis-Gutmann-bodies as a marker for malakoplakia, which rarely occurs in the skin. In further electron microscopic investigation, intracytoplasmatic bacteria could be demonstrated. An underlying malignancy or chronic renal insufficiency with immunosuppression were not found in this patient; both are often associated with malakaplakia.
    Notes: Zusammenfassung Es wird über einen 58jährigen Patienten berichtet, bei dem seit 20 Jahren rezidivierend eine Psoriasis vulgaris mit typischen erythemato-squamösen Plaques an den Prädilektionsstellen besteht. Desweiteren fand sich perianal ein seit ca. 5 Jahren bekannter, therapieresistenter und teils erodierter Plaque. Die zum Ausschluß eines malignen Prozesses durchgeführte Probebiopsie ergab die seltene kutane Manifestation einer Malakoplakie durch den Nachweis der typischen intrazytoplasmatischen Michaelis-Gutmann-Körperchen sowie durch elektronenmikroskopisch nachweisbare intrazytoplasmatische Bakterien. Ein Tumorleiden oder eine Niereninsuffizienz mit entsprechender Immunsuppression, als häufig beobachtete Grunderkrankung der ätiopathogenetisch bisher nicht geklärten Malakoplakie, konnten bei dem hier vorgestellten Fall ausgeschlossen werden.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Intensive care medicine 20 (1994), S. 278-281 
    ISSN: 1432-1238
    Keywords: Blood brain barrier ; Urapidil ; Serotonin-(5HT1A) ; Receptors ; Cerebrospinal fluid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective To determine the plasma and cerebrospinal fluid (CSF) levels of urapidil after i.v. administration and the effect on CSF serotonin and 5-hydroxyindoleacetic acid (5-HIAA) concentrations. Design Open, single-dose study. Setting Post-surgery following neurosurgical removal of the hypophysis (n=5) or aneurysm clipping (n=1). Patients 6 patients, aged 32–71 years, with intact bloodbrain barrier (BBB); 1 patient was studied twice. Interventions Single dose of 25 mg urapidil i.v. as prophylaxis of BP increase during extubation or as treatment of hypertensive episodes. Measurements and results Urapidil, serotonin and 5-HIAA were measured by HPLC in CSF during 8 h after urapidil administration. Urapidil was detected in CSF as soon as 5 min after injection in 3 patients. The concentration ratio of plasma/CSF after the distribution phase was about 5∶1. No significant effect on serotonin and 5-HIAA in CSF was seen. Conclusion After administration of a therapeutic dose, urapidil permeates the BBB and may interact with central 5-HT1A-receptors.
    Type of Medium: Electronic Resource
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