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 58 (1980), S. 889-896 
    ISSN: 1432-1440
    Keywords: Bezafibrat ; Niereninsuffizienz ; Pharmakokinetik ; Dosierungsschema ; Renale Clearance ; Extrarenale Clearance ; Bezafibrate ; Pharmacokinetics ; Dosage scheme ; Renal failure ; Renal clearance ; Extrarenal clearance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The pharmacokinetics of bezafibrate were investigated in the serum and urine of 22 patients with impaired renal function of different degrees after a single oral dose. The results of the first study were checked by a second study in another 12 patients with advanced renal insufficiency using multiple dosing. Both studies revealed an almost identical hyperbolic relationship between the mean serum concentration over 24 h and the endogenous creatinine clearance. Since the vertex of this hyperbola is positioned at a creatinine clearance of 50 ml/min, only greater impairment of the renal function requires dose reduction, the respective nomograms and schedules for which are given. Even in advanced renal failure (creatinine clearance 10–25 ml/min) the total serum clearance of bezafibrate was considerably higher (27 ml/min) than that reported in the literature for clofibric acid. It is of interest to note that not only the renal but also the “extrarenal” clearance, which in normals accounts for approximately half of the total clearance of bezafibrate, was considerably depressed in advanced renal failure. This might indicate that part of the extrarenal mechanism of bezafibrate elimination, e.g. the glucuronidation, might occur in the kidneys. Knowledge of the kinetic behaviour of bezafibrate in patients with impaired renal function also allows rational therapy in the presence of this condition.
    Notes: Zusammenfassung Die Pharmakokinetik von Bezafibrat wurde in Serum und Urin von 22 Patienten mit unterschiedlich eingeschränkter Nierenfunktion nach einmaliger oraler Gabe untersucht. Die hierbei gewonnenen Ergebnisse wurden in einer zweiten Studie bei 12 weiteren Patienten (Kreatinin Clearance 10–25 ml/min) unter steady-state-Bedingungen überprüft. Beide Studien ergaben eine nahezu identische hyperbole Beziehung zwischen der mittleren Serumkonzentration über 24 h und der endogenen Kreatinin-Clearance. Da der Scheitel dieser Hyperbel bei einer Kreatinin-Clearance von ca. 50 ml/min, liegt, ist eine Dosis-Reduktion erst bei weitergehender Einschränkung der Nierenfunktion erforderlich. Entsprechende Nomogramme und Dosisempfehlungen werden angegeben. Selbst bei fortgeschrittener Niereninsuffizienz (Kreatin-Clearance 10–25 ml/min) ist die totale Clearance des Bezafibrats noch mehrfach höher (27 ml/min) als die in der Literatur unter vergleichbaren Bedingungen für Clofibrinsäure bestimmte. Interessanterweise ist nicht nur die renale, sondern auch die extrarenale Clearance von Bezafibrat, die normalerweise ca. die Hälfte der totalen Clearance ausmacht, bei fortgeschrittener Niereninsuffizienz deutlich vermindert. Dies weist darauf hin, daß ein Teil der „extrarenalen“ Eliminationsmechanismen des Bezafibrat, z.B. der Umsatz zu Glucuronsäurekonjugaten auch in der Niere ablaufen dürfte. Insgesamt erlaubt nun die Kenntnis der Pharmakokinetik des Bezafibrat bei Niereninsuffizienz eine rationale Therapieführung bei derartigen Patienten.
    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
    Behavioral ecology and sociobiology 47 (2000), S. 188-194 
    ISSN: 1432-0762
    Keywords: Key words Caste determination ; Camponotus ants ; Morphometrics ; Microsatellites ; Allometry ; Polygyny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Genetic influences on polyethism within social insect colonies are well known, suggesting that the determination of caste (soldiers and minor workers) may also be genetically mediated. The Australian sugar ant Camponotus consobrinus is suitable for such a study, having soldiers and minor workers that follow a complex allometry. Further, although most C. consobrinus colonies are monogynous, 13 of 42 surveyed using microsatellites were found to be polygynous. Thus, although a minority of colonies were polygynous, the great majority of queens live in polygynous colonies. From the 29 monogynous colonies studied, we inferred that the queens are monandrous. Ants from four polygynous colonies were assigned to families on the basis of microsatellite genotypes, after measurements had been taken of head width and scape length. These measurements reflect a complex allometry interpretable as soldier and minor worker growth curves with a large changeover zone. Genetic influence on caste determination was examined by testing for differences between families within colonies in the distribution of scape lengths, residuals from the overall colony allometric curve, and proportions of soldiers and minor workers (as determined by head width falling above or below the inflection point of the overall colony allometric curve). Families in all four colonies differed significantly in caste proportions and in head-width distributions, and three of the four colonies showed significant differences between families in residuals from the overall colony growth curve. Nested ANOVAs using head widths and scape-length residuals showed that when the effect of family is removed, intercolony differences in allometry are negligible. This evidence indicates genetic rather than environmental causes for the observed differences between families. We speculate that this variation may reflect some selective advantage to within-colony heterogeneity between families or that selective differences are few between a wide array of family growth patterns.
    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...