Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 59 (1981), S. 1349-1351 
    ISSN: 1432-1440
    Keywords: Antithrombin III ; Plasma elimination Half-life ; Consumption coagulopathy ; Antithrombin III ; Plasma-Eliminations-Halbwertszeit ; Verbrauchskoagulopathie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Im Verlauf einer schweren Gerinnungsstörung bei einem Säugling mit Sepsis und Schock wurden vor und während der Substitutionsbehandlung mit humanem Antithrombin wiederholt die Antithrombin-III Spiegel gemessen. Diese Daten wurden mit Hilfe einer Biexponentialfunktion mathematisch ausgewertet. Die Plasma-Eliminations-Halbwertszeit des Antithrombins betrug 7,5 bzw. 10,5 Stunden. Verglichen mit bekannten Plasma-Halbwertszeiten von radioaktiv markiertem Antithrombin III bei Erwachsenen war die Elimination um den Faktor 5–10 beschleunigt. Die deutlich erniedrigten Antithrombin III Spiegel in diesem Fall konnten also mindestens teilweise auf einen beschleunigten Umsatz des Antithrombins zurückgeführt werden. Die Bestimmung der Plasma-Eliminations-Halbwertszeit von Antithrombin III ist hilfreich bei der Abgenzung einer verminderten Produktion von einem gesteigerten Umsatz im Verlauf einer Koagulopathie. Die Diagnose einer disseminierten intravasalen Gerinnung kann so etwas sicherer gestellt werden. Die Vorteile der Antithrombin- Substitutionstherapie werden bei diesem Vorgehen genützt, die Nachteile radioaktiv markierter Proteine vermieden.
    Notes: Summary During the course of severe coagulopathy in an infant suffering from septicaemia and shock, antithrombin III levels were determined repeatedly before and during substitution therapy with human antithrombin. By mathematical analysis of these data, using a biexponential function, the plasma elimination half-life of the antithrombin III was estimated to be 7.5–10.5 h. Compared with known plasma half-lives of radioactively labelled antithrombin III in adults the increase was five-to ten-fold. This indicates that the significantly decreased levels of antithrombin III in this case of coagulopathy were at least partly due to an accelerated consumption of antithrombin III. The estimation of the plasma elimination half-life of antithrombin III helps to differentiate decreased production from increased consumption in cases of severe coagulopathy. Thus, a more precise diagnosis of disseminated intravascular coagulation can be made whilst taking advantage of substitution therapy and avoiding the hazards of radioactive tracer proteins.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 141 (1984), S. 225-227 
    ISSN: 1432-1076
    Keywords: Antithrombin III (heparin cofactor activity) ; Plasma elimination half-life ; Newborn infants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Antithrombin III (AT III) levels are markedly increased in newborn infants following exchange transfusion with adult blood, and subsequently return to pre-exchange values. This transient rise in AT III (heparin cofactor activity), was used to estimate its plasma elimination half-life. AT III activities were measured serially, before and after double-volume exchange transfusions with heparinised blood in newborn infants requiring therapy for severe hyperbilirubinaemia. The plasma elimination half-life of AT III activity was calculated to be 3.9±1.4 h ( $$\overline X = 2.05$$ ±SEM). Compared with published data on the kinetics of AT III infusions in adults, the neonate has a considerably accelerated turnover. This finding has important implications for the design of future therapeutic trials of AT III concentrates and provides further evidence that plasma proteins, including components of the coagulation system, appear to have different kinetics in the neonatal period.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 661-665 
    ISSN: 1432-1041
    Keywords: hydrochlorothiazide ; pharmacokinetics ; renal failure ; dosage adjustment ; excretory mechanism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of hydrochlorothiazide (HCT) was investigated in 23 subjects with normal renal function or widely varying degrees of renal failure. The half-life of elimination increased from 6.4 h in subjects with normal renal function to 11.5 h in patients with mild renal impairment (endogenous creatinine clearance between 30 and 90 ml/min), and to 20.7 h in patients with an endogenous creatinine clearance below 30 ml/min. The cumulative urinary excretion and the renal HCT clearance were correspondingly reduced in patients with impaired kidney function. In normal subjects HCT was mainly excreted by tubular secretion, but as renal HCT clearance in patients with renal impairment did not differ significantly from endogenous creatinine clearance, it was concluded that the secretory mechanism is most markedly impaired. In patients with an endogenous creatinine clearance of 30 to 90 ml/min, the dosage of HCT should be reduced to 1/2 and in patients with a endogenous creatinine clearance below 30 ml/min to 1/4 of the normal daily dose to avoid dose dependant side-effects.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 292 (1976), S. 189-192 
    ISSN: 1432-1912
    Keywords: Amiloride ; Ouabain ; Active transport of Na+, K+, H+/HCO 3 - ; Membrane ATPases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The submaxillary duct epithelium, which actively transports Na+ (rabbit) and, in addition, K+ and H+/HCO 3 - (rat), was used as a model epithelium to compare the effects of ouabain and amiloride on transport parameters. 1. Ouabain was only effective from the interstitial side, amiloride, however, only from the luminal side. Amiloride induced effects on transport of the ions were seen within less than 1 s, ouabain effects, however, only after minutes. 2. Ouabain inhibited in a parallel fashion the Na+ transport potential and the Na+−K+-ATPase activity. It had no effect on the Mg2+-ATPase and the HCO 3 - -ATPase. 3. Amiloride also inhibited the Na+ transport potential and the Na+−K+-ATPase; however, the Na+ transport potential was significantly more sensitive to amiloride than the Na+−K+-ATPase. 4. Amiloride inhibited in a similar fashion the Na+−K+-ATPase, the Mg2+-ATPase and the HCO 3 - -ATPase, but did not influence active HCO 3 - secretion. 5. It is concluded that the amiloride induced effects on the membrane ATPases are non-specific.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 361 (1975), S. 61-64 
    ISSN: 1432-2013
    Keywords: H+ transport ; HCO 3 − ATPase ; Acidosis ; Alkalosis ; Salivary duct
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ATPase stimulated by HCO 3 − ions and other oxybases and inhibited by SCN− has been found in main exeretory duct of rat submaxillary gland, a tissue, capable of actively secreting HCO 3 t- ions. No such ATPase was found in the rabbit duct, which normally does not secrete HCO 3 − . The HCO 3 − ATPase was localized in the plasma membrane fraction of the homogenate, as evidenced by the marker 5′-nucleotidase. The activities of the HCO 3 − ATPase increased in metabolic alkalosis and decreased in metabolic acidosis in parallel to secretion of HCO 3 − and K+ ions by the duct epithelium. These findings provide further evidence that the membrane-bound HCO 3 − ATPase is involved in active H+/HCO 3 − transport.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1435-1803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An isolierten Papillarmuskeln von Meerschweinchen wurde die zeitabhängige antwort des Ca++-Aktionspotentials bei Änderungen der extrazellulären Ca++-Konzentration unter verschiedenen experimentellen Bedingungen analysiert. Nach Erhöhung der extrazellulären Ca++-Konzentration von 0,2 mM auf 2 mM steigen Aufstrichsgeschwindigkeit und Overshoot an und erreichen ihre Steady-state-Werte mit Zeitkonstanten τRegeneration von 80–200 s. Die für das Erreichen des Steady-state notwendige Zeit steigt nach Temperatur-Senkung an. Die für τRegeneration errechneten Temperaturkoeffizienten betragen 1,8–2,0. Isoproterenol (1 mg/l) rief eine drastische Senkung von τRegeneration bis auf 11 s hervor. Dieser Effekt blieb nach Blockade des β-Rezeptors aus und ließ sich auch durch Theophyllin hervorrufen. Nach Senkung der extrazellulären Ca++-Konzentration von 2 mM auf 0,2 mM erfolgte eine allmähliche Abnahme von Aufstrichsgeschwindigkeit und Overshoot, bis schlie\lich 50–120 s nach Lösungswechsel das Ca++-Aktionspotential verschwunden war. Die Dauer der Persistenz des Ca++-Aktionspotentials in Ca++-armer (0,2 mM) Lösung ist pH-abhängig und nahm bei Senkung des pH ab. Ein Anstieg der Persistenz-Dauer erfolgte in Gegenwart von Isoproterenol oder Theophyllin und trat auch dann in Erscheinung, wenn das Präparat nach Ca++-Entzug nicht fortlaufend gereizt wurde. Der gleiche Effekt zeigte sich, wenn die Präparate vor Umschalten auf die Ca++-arme Lösung erhöhten Ca++-Konzentrationen ausgesetzt worden waren. Allerdings ergab sich keine lineare Abhängigkeit der Persistenzdauer von der initialen Ca++-Konzentration. Vielmehr existiert eine Sättigungscharakteristik. Die Ergebnisse lassen sich mit der Annahme erklären, daß die als Ladungsträger des langsamen Einwärtsstromes fungierenden Ca++-Ionen nicht unmittelbar aus dem Extrazellulärraum, sondern aus einem oberflächlich lokalisierten Ca++-Pool der Membran stammen.
    Notes: Summary In isolated papillary muscles of guinea pigs the time-dependent changes of the Ca-mediated action potential due to variations of the external Ca concentration were analyzed under different experimental conditions. After an increase of the external Ca concentration from 0.2 mM to 2 mM, upstroke velocity and overshoot of the Ca-mediated action potential attained their steady state values with time constants ranging from 80 to 200 s (τregeneration). A decrease of temperature from 35°C to 30°C led to an increase of τregeneration and temperature coefficients between 1.8 and 2.0 were calculated. The β-stimulating compound isoproterenol (1 mg/l) caused a decrease up to 11 s that is prevented by pretreatment with the β-receptor blocking agent pindolol (2 mg/l). This accelerating effect of isoproterenol on the regeneration of the Ca-mediated action potential was mimicked by theophylline. After switching to a Ca-poor (0.2 mM) solution, the Ca-mediated action potential disappeared within 50–120 s. This time of persistence in a Ca-poor environment was abbreviated by lowering the extracellular pH. Isoproterenol and theophylline prolonged the time of persistence. The same effect occurred after interruption of the continuous stimulation during the washout of Ca. The sensitivity of the Ca-mediated action potential towards Ca-withdrawal decreased when the Ca concentration prior to switching to the Ca-poor solution was higher than 2 mM. But there was no linear dependence of the time of persistence on the initial Ca concentration. Rather a saturation characteristic was found. The results suggest that the actual charge carrier of the slow inward current, Ca ions, might originate from a superficially located Ca pool of the cardiac membrane.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...