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  • Computed tomography  (2)
  • Comparative life histories  (1)
  • Essentielle Hypertonie  (1)
  • Gallbladder contraction  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Fat cycling in the mosquitofish (Gambusia affinis): fat storage as a reproductive adaptation (1987)
    Springer
    Oecologia 73 (1987), S. 401-413 
    Details
    ISSN: 1432-1939
    Keywords: Gambusia affinis ; Fat storage ; Life history strategy ; Reproductive cycles ; Comparative life histories
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We argue, based on reviewed literature covering reptiles, amphibians, birds, and fish, that fat storage may represent a life history adaptation because it enables an organism to shift in time when resources are allocated to reproduction. We applied these arguments to fat and population cycles in three populations of the mosquito fish, Gambusia affinis. For males, there appeared to be a constant size at maturation during the reproductive season. Mature males became scarce late in the summer. At the same time, immature males delayed maturity and attained much larger sizes; they matured in large numbers in the fall. The amount of stored fat tended to be equal for immature and mature males at all times except in the late summer. In the August samples, when mature males were relatively rare, they also had the lowest level of fat reserves. It appears that the older generation of mature males did not store fat and did not overwinter. At the same time, immature males registered a two to three fold increase in fat reserves. These differences in fat content between mature and immature males disappeared by September, probably because of the recruitment of a new generation of mature males. The reserves were gradually utilized during the winter. Females reproduced from the late spring through mid- to late-summer. They stopped reproducing in the late summer, when there was ample time to produce an additional litter of young. There was an inverse relationship between resources devoted to reproduction and fat reserves. As reproductive allotment decreased in the late summer, fat reserves increased. The magnitude of the change in fat reserves was similar to that displayed by males. The reserves were depleted over the winter. Significant reserves remained at the beginning of the reproductive season the following spring. Reproducing females utilized the remaining reserves significantly more rapidly than non-reproducing females. An analysis of resource availability revealed an overall decrease in food availability in the late summer, coincident with the increase in fat reserves. These cycles are therefore not attributable to changes in resource availability. They instead indicate a change in how resources are allocated by the fish. The trends in the data indicate that fat reserves are used to shift investment in reproduction from the late summer to the following spring. In males, deferring maturity, rather than maturing in August, allows them to store the necessary reserves to survive the winter so that they can mate the following spring. In females, a subset of the fat reserves is intended for producing the first clutch of eggs the following spring. The female pattern corresponds to those reported for a diversity of organisms. The possible advantages of shifting reproductive effort from the fall to the following spring include higher fecundity and higher offspring fitness. The limitations of the methodology and potential directions for future research are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00385257
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  • 2
    Electronic Resource
    Electronic Resource
    Changes in gallbladder motor function during the female cycle — a risk factor leading to gallstone formation? (1982)
    Springer
    Journal of molecular medicine 60 (1982), S. 1357-1362 
    Details
    ISSN: 1432-1440
    Keywords: Gallbladder motor function ; Gallstone formation ; Gallbladder ultrasonography ; Gallbladder contraction ; Gallbladder refilling ; Gallensteinentstehung ; Gallenblasenkontraktion ; Motorische Gallenblasenfunktion ; Gallenblasenfüllung ; Ultraschalldiagnostik
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei 8 Frauen mit stabilem Zyklus wurden mittels Sonographie das Gallenblasenvolumen bestimmt und in der Progesteron- sowie der Östrogenphase des Zyklus die Gallenblasenkontraktion nach oraler Reizmahlzeit und die spontane Wiederauffüllung der entleerten Gallenblase quantitativ untersucht. Zur Volumenberechnung wurde die Formel eines Drehellipsoids verwandt, die sich im Modellversuch als hinreichend exakt erwiesen hatte. Die intraindividuellen Vergleichsuntersuchungen zeigten in der Progesteronphase (21. oder 22. Tag) gegenüber der östrogenphase (12. oder 13. Tag) statistisch gesicherte größere Nüchternvolumina, höhere Residualvolumina nach Kontraktion und eine langsamere Gallenblasenentleerung sowie eine verzögerte Wiederauffüllung der entleerten Gallenblase. Dem hormonal modifizierten Kontraktionsverhalten und der unterschiedlich ablaufenden Gallenblasenfüllung könnte im Rahmen der Gallensteinentstehung eine wesentliche Bedeutung zukommen.
    Notes: Summary The gallbladder volume of eight women with stable cycles was determined by sonography. Furthermore, gallbladder contraction — following an orally administered fatty meal and the spontaneous refilling of the empty gallbladder — was quantitatively examined. The formula of a rotation ellipsoid, which has been proven to be adequately accurate in in vitro studies, was used for calculating the gallbladder volume. In the gestagen phase (21st or 22nd day) the intraindividual studies showed greater fasting volumes, higher residual volumes after contraction, slower gallbladder emptying, and retarded refilling of the empty gallbladder as compared to the estrogen phase (12th or 13th day). The hormonally modified contraction behavior and the differing course of gallbladder filling may play a major role in the pathogenesis of gallstone formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01716215
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  • 3
    Electronic Resource
    Electronic Resource
    Verhalten der Plasmareninaktivität unter Langzeitbehandlung des Hochdrucks mit Propranolol (1977)
    Springer
    Journal of molecular medicine 55 (1977), S. 351-353 
    Details
    ISSN: 1432-1440
    Keywords: Plasma renin activity ; Long-term treatment ; Propranolol ; Essential hypertension ; Propranolol ; Essentielle Hypertonie ; Plasmareninaktivität ; Langzeitbehandlung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 17 Patienten im Alter von 40±9 Jahren mit essentieller Hypertonie wurden mit Propranolol als Monotherapie oral in Dosen von 120, 160 oder 240 mg pro die behandelt. Nach 4wöchiger Behandlung konnten der Blutdruck und die Herzfrequenz statistisch signifikant gesenkt werden und blieben auch bei Fortsetzung der Therapie nach insgesamt 6 Monaten unverändert. Die Plasmareninaktivität betrug vor Behandlungsbeginn 5,7±6,3 ng/ml/h und sank nach 4wöchiger Behandlung auf 1,8±1,3 ng/ml/h ab. 5 Monate später stieg das Plasmarenin im Durchschnitt wieder auf 5,0±0,9 ng/ml/h an. Der erneute Anstieg war ebenfalls statistisch signifikant zu sichern. Von den 17 Patienten hatten nach 6 monatiger Therapie noch 7 (41%) eine niedrigere Plasmareninaktivität als vor Behandlungsbeginn. Davon lagen aber nur 3 (18%) unter dem Wert, der nach 4wöchiger Behandlungsdauer bestimmt wurde. Aus den genannten Befunden wird geschlossen, daß der Wiederanstieg der Plasmareninaktivität möglicherweise ein reaktiver Mechanismus auf die langzeitige Blutdrucksenkung ist. Die Erniedrigung der Plasmareninaktivität nach Kurzzeitbehandlung mit Propranolol kann nicht als ein Mechanismus für den antihypertensiven Effekt dieses Medikaments bei der Langzeitbehandlung angesehen werden.
    Notes: Summary 17 patients (40±9 years) with essential hypertension were included in the study. A monotherapy of 120, 160 or 240 mg propranolol per day was administered orally according to the antihypertensive effect. Four weeks after treatment, blood pressure and heart rate showed a statistically significant decrease and remained unchanged over a period of six months. Plasma renin activity decreased significantly from 5.7±6.3 ng/ml/h at the beginning of the study to 1.8±1.3 ng/ml/h after 4 weeks. 5 months later however plasma renin activity increased again to 5.0±0.9 ng/ml/h. The difference was statistically significant. From 17 patients 7 (41%) had lower levels of plasma renin activity after 6 months treatment when compared with pretreatment values. In only 3 patients (18%) was plasma renin activity lower after 6 months than after four weeks. We conclude that the increase in plasma renin activity is a reactive mechanism to the reduced blood pressure under long-term conditions. The decrease of plasma renin activity in short-term treatment of essential hypertension is not a mechanism responsible for the antihypertensive effect of propranolol during long-term treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01488116
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  • 4
    Electronic Resource
    Electronic Resource
    Wertigkeit moderner Verfahren zur Lokalisation von Phäochromocytomen (1979)
    Springer
    Journal of molecular medicine 57 (1979), S. 1209-1215 
    Details
    ISSN: 1432-1440
    Keywords: Pheochromocytoma localization ; Plasma catecholamines ; Adrenal phlebography ; Ultrasonography ; Computed tomography ; Phäochromocytomlokalisation ; Plasmakatecholamine ; Nebennierenphlebographie ; Sonographie ; Computer-Tomographie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei sechs Patienten mit adrenalem Phäochromocytom erfolgte die Lokalisationsdiagnostik durch Ultraschalluntersuchung, Phlebographie der Nebennieren und selektiver Katecholaminbestimmung im Blut der Vena cava sowie der Nebennierenvenen. Durch die selektive Katecholaminbestimmung konnten alle Phäochromocytome lokalisiert werden, durch die Ultraschalluntersuchung fünf, durch die Phlebographie vier. Ein Phäochromocytom von 1,5 g Gewicht, das nur durch die selektive Katecholaminbe-stimmung, nicht aber durch Ultraschall oder Phlebographie lokalisiert wurde, konnte computertomographisch dargestellt werden. Um Fehldiagnosen bei der selektiven Katecholaminbestimmung zu vermeiden, darf vor der Blutentnahme aus den Nebennierenvenen kein Röntgenkontrastmittel injiziert werden, da dies zu einer erheblichen Adrenalin- oder Noradrenalinfreisetzung aus dem Nebennierenmark führen kann.
    Notes: Summary In six patients with adrenal pheochromocytoma the tumors were localized by ultrasonography, phlebography of the adrenal glands and by estimation of plasma catecholamines selectively obtained from the vena cava and the adrenal gland veins. All tumors were localized by selective catecholamine estimation, five by ultrasonography, and four by phlebography. The smallest pheochromocytoma of 1.5 g weight was only localized by selective catecholamine estimation but not by ultrasonography or phlebography. This tumor, however, had been visualized by computed tomography. To avoid diagnostic errors by selective catecholamine estimation, it is important to withdraw blood from the adrenal gland veins prior to the injection of any radiographic contrast media, since this may result in an extremely enhanced secretion of catecholamines from the adrenal medulla.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01489248
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  • 5
    Electronic Resource
    Electronic Resource
    Der Einfluß von Sonographie und Computer-Tomographie auf die operative Behandlung der akuten Pankreatitis (1982)
    Springer
    Langenbeck's archives of surgery 356 (1982), S. 141-149 
    Details
    ISSN: 1435-2451
    Keywords: Acute pancreatitis ; Computed tomography ; Ultrasound ; Operative treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die „stadiengerechte Therapie” der akuten Pankreatitis, die jedem Schweregrad der Erkrankung angemessen ist, besteht neben der konservativen Basistherapie und Intensivmedizin im richtigen Einsatz operativer Maßnahmen. Voraussetzung dafür ist die frühe Diagnose und Beurteilung des Schweregrades der akuten Pankreatitis. Neben klinischen und klinisch-chemischen Befunden und dem Verlauf unter konservativer Therapie ermöglichen die Sonographie und die Computer-Tomographie eine bessere Beurteilung der jeweiligen Verlaufsform. Die für die Klinik der Erkrankung so wichtigen morphologischen Veränderungen der Bauchspeicheldrüse und ihrer Umgebung werden durch diese neuartigen Untersuchungsmethoden transparenter. Wäh rend bei der leichten Pankreatitis die Sonographie als erstes morphologisches Untersuchungsverfahren eingesetzt wird, besteht bei den schweren Verlaufsformen eine klassische Indikation zur Computer-Tomographie. Durch Einsatz von Sonographie und Computer-Tomographie läßt sich die Indikation zur frühzeitigen oder verzögerten Operation der hämorrhagisch-nekrotisierenden Pankreatitis, die bisher nach klinischen Kriterien erfolgte, in den meisten Fällen exakter stellen.
    Notes: Summary Adequate stage-depending therapy of acute pancreatitis includes basic conservative treatment, intensive care measurements, and operative interventions depending on the grade of severity. Prerequisites are early diagnosis and accurate clinical assessment of the stage of severity. Beside clinical and laboratory findings, as well as the development of acute pancreatitis under conservative treatment, sonography and computed tomography allow a better prediction of the underlying morphological changes, thus leading to an exact staging of the patient's individual situation. Sonography is regarded a screening procedure of high accuracy in mild forms of acute pancreatitis. Computed tomography is the method of choice in all severe forms of this disease. The indication for immediate or delayed operative treatment of hemorrhagic necrotising pancreatitis, heretofore depending on clinical findings solely, is supported by these new-invasive diagnostic modalities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01239461
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    Paper (German National Licenses)
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