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  • 1980-1984  (2)
  • 1915-1919
  • 6-Hydroxydopamine  (1)
  • Cardiac output  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 59 (1981), S. 1115-1120 
    ISSN: 1432-1440
    Keywords: Cardiac output ; Non-invasive ; Echocardiography ; Dye dilution ; Herzminutenvolumen ; nicht-invasiv ; Echocardiographie ; Farbstoffverdünnungstechnik
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Einer nicht invasiven Methode zur akkuraten Bestimmung des Herzminutenvolumens (HMV) käme eine große Bedeutung zu. Wir verglichen deshalb aus links-ventriculären Echocardiogrammen bestimmte mit gleichzeitig mittels Farbstoffverdünnungsmethode (Cardiogreen) bestimmten HMV in 10 normalen Versuchspersonen. Unter Ruhebedingungen war das HMV mit beiden Methoden reproduzierbar und nicht signifikant verschieden. Anstiege des HMV nach intravenöser Infusion von Isoproterenol (15 ng/kg/min über 4 min) wurden mittels Echocardiographie zuverlässig nur bei Probanden erfaßt, bei denen das Schlagvolumen weniger als 40% anstieg. Bei größeren Anstiegen wurde der Anstieg des HMV signifikant unterschätzt. Ein erniedrigtes HMV nach intravenöser Injektion von Propranolol (0,2 mg/kg) wurde von beiden Methoden gleichermaßen erfaßt. Obwohl das HMV mittels Echocardiographie für das Untersuchungskollektiv nicht signifikant von den Farbstoffverdünnungswerten verschieden war, wichen die echocardiographisch bestimmten HMV bei einzelnen Probanden deutlich von den Farbstoffverdünnungswerten ab. Unsere Ergebnisse zeigen, daß die links-ventriculäre Echocardiographie zur Bestimmung des HMV in Gruppen und bei Änderungen des Schlagvolumens von weniger als 40% benutzt werden kann.
    Notes: Summary Because of the potential benefits from a noninvasive technique in assessing cardiac output, we compared cardiac output estimates from left ventricular echocardiograms with results obtained simultaneously by a standard technique, dye dilution in 10 healthy normal volunteers. During rest, cardiac outputs by echocardiographic and dye dilution techniques were reproducible and not significantly different. Increases in cardiac output produced by intravenous infusion of isoproterenol (15 ng/kg/min for 4 min) were accurately estimated by echocardiography in subjects whose stroke volume increased less than 40%, but were significantly underestimated when stroke volume increased more than 40%. Decreased cardiac output produced by intravenous propranolol (0.2 mg/kg) was comparable by both methods. Although echocardiography accurately estimated mean cardiac output for the group it over- or underestimated cardiac output in individual subjects. We propose that echocardiography can reliably estimate cardiac output in groups at rest and when stroke volume changes less than 40%.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 79 (1983), S. 115-119 
    ISSN: 1432-2072
    Keywords: Dopamine ; Acquisition ; Brain lesions ; 6-Hydroxydopamine ; Neonatal rat ; Operant behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In an attempt to examine the ability of brain dopamine (DA) depletion to alter learning ability in the developing rat, the rate of acquisition of a positively reinforced lever pressing response was examined in rats during days 30–45 of life following treatment with desmethylimipramine (DMI, 20 mg/kg IP) and 6-hydroxydopamine (6-OHDA, 35 μg intraventricularly) at 3 and 6 days of age, respectively. The 6-OHDA treatment produced a 40%–70% reduction of brain DA without altering growth rate, water intake, or locomotor activity. On the average, water-deprived control rats achieved the criterion for acquisition (50 reinforced lever presses/h) on a fixed-ratio 1 schedule of water reinforcement after 3.1±0.5 sessions (mean ± SEM). In contrast, nearly one-fourth of the DMI + 6-OHDA-treated rats failed to acquire the response after 16 sessions and the remaining 6-OHDA-treated rats required more than twice as long as controls for acquisition (7.8±0.7 sessions). These results suggest that brain DA depletion in neonatal life can impair the acquisition of an operant response during development and that this deficit is independent of changes in growth rate or locomotor activity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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