ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 17 (1980), S. 425-428 
    ISSN: 1432-1041
    Schlagwort(e): prazosin ; congestive heart failure ; pharmacokinetics ; oral dose ; comparison with healthy volunteers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The pharmacokinetics of prazosin (Minipress®) were studied in nine patients with NYHA Class 3 or 4 congestive heart failure and in five healthy controls. After a single 5 mg oral dose, plasma concentrations of prazosin, as reflected in the area under the plasma concentration-time curve (AUC) and prazosin plasma half-life, were approximately double in the patients in comparison to the control group. Reduction in hepatic blood flow, altered gastrointestinal absorption of the drug or diminished intrinsic hepatic metabolic activity in the patient group may have contributed to the observed changes in prazosin disposition. The finding of higher prazosin plasma concentrations in patients with refractory heart failure demonstrates the need for close monitoring of these individuals following administration of the drug in the treatment of chronic congestive heart failure.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 27 (1984), S. 291-296 
    ISSN: 1432-1041
    Schlagwort(e): naproxen ; cirrhosis ; pharmacokinetics ; protein binding ; nonsteroidal antiinflammatory drugs
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Chronic liver disease is known to alter the absorption and disposition of many drugs. To assess the influence of chronic alcoholic liver disease on the disposition of naproxen, we administered the drug both as a single dose and to steady state to 10 individuals with alcoholic cirrhosis and to 10 healthy controls. Plasma and serum samples collected after naproxen dosing were assayed for both total and (following equilibrium dialysis) unbound drug concentration. Clearance calculated based on both total and unbound naproxen concentration revealed no change in total plasma clearance of the drug at steady state but a marked reduction of approximately 60% in clearance based on unbound drug. Naproxen volume of distribution changed only minimally. Because clearance based on unbound drug concentration at a given dosing rate determines the plasma or blood free drug concentration, this concentration may increase significantly in patients with alcoholic liver disease given usual doses of naproxen. Unbound drug concentration is thought to determine the pharmacologic effect of a drug. We therefore recommend that naproxen dosing be reduced by at least half in patients with chronic alcoholic liver disease. In the absence of data to the contrary, this recommendation can be extended to individuals with other forms of hepatic disease.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 20 (1981), S. 127-133 
    ISSN: 1432-1041
    Schlagwort(e): ketoprofen ; pharmacokinetics ; multipledose ; bioavailability ; assay ; modelling
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary A commercial capsule containing 50 mg of ketoprofen (Orudis), a simple capsule containing 50 mg of ketoprofen alone and 50 mg of ketoprofen in an aqueous solution were given as separate doses in a randomized sequence to 12 normal adult males. The areas under the resulting plasma concentration-time curves (AUC) were remarkably consistent for each volunteer. The bioavailability from the commerical capsule relative to that from the solution was 99.7%±10.5% and that from the simple capsule was 102%±10%. After 6 of the volunteers had taken the commercial capsule 6 hourly for thirteen doses, their AUC extrapolated to infinity was significantly higher (by 22%) than that after the single dose indicating, contrary to previous reports, accumulation upon multiple dosing. The interdose AUC after the thirteenth dose was, however, statistically indistinguishable from the AUC-to-infinity after the single dose as might be expected from linear kinetics. The ketoprofen solution generated peak plasma concentrations in only one-third the time (21±7 min) required for the capsules (commercial, 72±45; simple, 61±39 min). Despite plasma concentrations being tracked over a 200-fold range, log linearity was not established within 12 h in any of the 42 profiles obtained. A two-compartment open model was fitted to the solution data giving excellent prediction of the time-to-peak and clearance (Cl/F=5.2±1.1 l/h) as determined by eye and by log-trapezoidal rule, respectively.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Bulletin of environmental contamination and toxicology 11 (1974), S. 343-347 
    ISSN: 1432-0800
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 33 (1977), S. 626-627 
    ISSN: 1420-9071
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of i.p. injections of amphetamine and apomorphine were determined before and after unilateral ligation of the carotid artery in the gerbil. Significant increases in turning behavior were observed in the absence of neurohistological evidence of infarction.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    ISSN: 1573-904X
    Schlagwort(e): primidone ; bioavailability ; human ; pharmacokinetics ; in vitro dissolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Purpose. To determine if large differences in the in vitro dissolution profiles for primidone tablets would result in significant bioavailability differences. Methods. Two separate bioavailability studies were conducted. The first study used 18 healthy subjects and compared the bioavailability of an old 50 mg tablet formulation, a new 50 mg tablet formulation, and a suspension containing 50 mg/ml of primidone. The second study enrolled 24 subjects who were to receive a new 250 mg tablet formulation, two lots of an old 250 mg tablet formulation and a 250 mg tablet from a second manufacturer. In vitro dissolution was conducted over 90 minutes, using USP 23 Apparatus 2 at 50 rpm, with 900 ml of water. Results. Dissolution at 90 minutes for the old and new 50 mg tablets was approximately 20% and 100%, respectively. The dissolution of the four 250 mg tablets ranged from approximately 30% to 100%. The 50 mg tablet that dissolved slower had a longer Tmax and a 14% lower Cmax than the more rapidly dissolving tablet, but the AUC(0−∞) values differed by only 3%. Only nine subjects completed the 250 mg study because of side effects. The differences in Cmax and AUC(0−∞) among the four 250 mg tablets were less than 7%. Conclusions. Even though there were large differences in the in vitro dissolution of the 50 mg and the 250 mg primidone tablets, the two 50 mg tablets were shown to be bioequivalent, as were the four 250 mg tablets.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Journal of materials science 5 (1994), S. 441-445 
    ISSN: 1573-4838
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Technik allgemein
    Notizen: The MTT test has been widely used as a rapid and sensitive method for screening anticancer drugs. In this paper, we used this method to assess the cytocompatibility of three materials: Keviar 29, silicon carbide and polyvinyl chloride (PVC) in both a quantitative and a qualitative manner. The materials were prepared by cleaning in 70% ethanol, autoclaved or gamma-sterilized. Extracts were prepared at four time periods (1, 2, 3 and 4 weeks) and two temperatures (37°C and 80°C). The extracts were used in the MTT assay and the data were collected and analysed with ONEWAY and DUNCAN procedures using the statistical computer package SPSSx. The MTT staining procedure was also used in direct contact with the materials. The result from the MTT assay demonstrated that Kevlar, SiC and PVC extracted at 37°C were not cytotoxic while PVC extracted at 80°C did show some cytotoxicity, especially the material that had been gamma-sterilized. In the direct contact test the Kevlar showed no cytotoxicity. The SiC did show some localized toxicity when the material had been autoclaved, however, SiC subject to prior cleaning with ethanol showed no cytotoxicity. The PVC that had been autoclaved caused a cytotoxic response whereas the material that had been gamma-sterilized or cleaned in ethanol showed good cytocompatibility. This paper demonstrates that the MTT staining procedure is a useful technique to study the cytocompatibility of materials in both a quantitative and a qualitative manner. It is also shown that the cellular response to the materials tested is dependent on the method of preparation.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Journal of materials science 6 (1995), S. 813-817 
    ISSN: 1573-4838
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Technik allgemein
    Notizen: The effect on neutrophil chemokinesis and fibroblast adhesion of changing surface topography was examined using two polymeric substrates; polycarbonate and polyetherimide, modified by laser treatment to produce pillars of varying dimensions on the surfaces of these materials. The dimensions for the pillars were 7,25 or 50 μm square, 0.5, 1.5 or 2.5 μm deep. Human neutrophils were isolated, by centrifugation, on ficoll from heparinized whole blood obtained from healthy volunteers. Isolated neutrophils were exposed to the surfaces for 20 min and tracked using image processing and analysis techniques. The mean speed for each cell on each surface was calculated and this data statistically analysed using multivariate analysis of variance to determine any significant effect on speed of movement due to the surface topography. Compared to the potent stimulator FMLP all surfaces did not stimulate significant cell movement, but within the groups some surfaces had more effect on cell movement than others, and were stimulating cells to move faster than on the same untextured surface. Surface topography can stimulate neutrophils to move at different speeds across a surface. L929 fibroblasts were incubated on the surfaces for 48 h and then examined using scanning electron microscopy to study fibroblast position and adhesion with respect to the pillars. No pattern of orientation with respect to the pillars were observed and fibroblasts spread and elongated whether in contact with the pillars or on a smooth area of the material.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Journal of materials science 5 (1994), S. 429-433 
    ISSN: 1573-4838
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Technik allgemein
    Notizen: This study investigates the biocompatibility of polypyrrole, a conducting polymer, and comments on its potential as an effective guidance channel for the regeneration of nervous tissue. The polymer was prepared in our laboratories by an electro-polymerization process. Pyrrole is placed in an electrolyte and when a potential is applied polypyrrole is deposited at the anode. After polymerization the polypyrrole is easily removed from the anode. Extraction in methanol for a period of 1 week was carried out to remove residual electrolyte. The biocompatibility of the material was assessed in vitro and in vivo. The response of two cell lines growing in contact with the polymer was evaluated. L929 mouse fibroblast and neuro2a neuroblastoma cells contacted the polypyrrole in a specially constructed cell culture chamber which allowed a controlled current to pass through the material. In vivo, the material was evaluated following implantation into a rat model. furthermore, the effect of charge on the cell lines was examined using the same cell culture chamber, but substituting platinum wire for the polypyrrole. Finally, the polypyrrole was deposited directly onto the platinum wire and introduced to the cell culture chamber. The results demonstrate that the polypyrrole is cytocompatible in vitro if prepared by appropriate extraction techniques. In vivo there was only a minimal tissue response after 4 weeks in situ. The cell culture chamber model proved successful and allowed a current up to 1 mA to be applied across the polypyrrole or platinum wire while in contact with both cell lines. Some evidence of toxicity was evident when a current of 1 mA was applied across the polymer for periods up to 96 h. However, it is clear from these experiments that polypyrrole can be an effective medium for carrying current in a biological environment.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Journal of materials science 8 (1997), S. 45-51 
    ISSN: 1573-4838
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Technik allgemein
    Notizen: Abstract Since many fibres are very strong, they are considered to have useful potential for fibre reinforcement of orthopaedic and dental implant materials. Fibres exposed on the surface of composites may significantly influence the cellular response not only due to the chemistry but also due to the fibre size and shape. This study has concentrated on investigation of cellular responses to fibre-specific aspects of fibre-reinforced composites. Four multifilament materials with diameter less than 20 μm were used: Kevlar 29(K), silicon carbide(SiC), nylon 66(N), and polyethylene terephthalate(PET). Established cell line L929 fibroblasts were used as the cell model. Cell behaviour on the surfaces of fibres was examined using direct cell counting (after 3, 5, 8 h and 1, 2, 3 days), scanning electron microscopy (SEM) (after 2 h and 2 days), and fluorescent staining of F-actin, which was analysed by confocal laser scanning microscopy (CLSM) (after 2 h and 2 days). The results showed that fibroblasts adhered and grew very well on all fibre surfaces, although less cells were observed on PET from direct cell counting. Significant orientational behaviour of cells was found on all fibre surfaces from the SEM and CLSM analysis, independent of the bulk chemistry of the fibres.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...