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  • Lepidoptera  (6)
  • protein binding  (6)
  • transport  (6)
  • Springer  (18)
  • American Physical Society
  • Annual Reviews
  • Springer Science + Business Media
  • 1980-1984  (18)
  • 1982  (18)
Collection
Keywords
Publisher
  • Springer  (18)
  • American Physical Society
  • Annual Reviews
  • Springer Science + Business Media
Years
  • 1980-1984  (18)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Plasma protein binding of etidocaine during pregnancy and labour (1982)
    Springer
    European journal of clinical pharmacology 22 (1982), S. 451-457 
    Details
    ISSN: 1432-1041
    Keywords: etidocaine ; protein binding ; pregnancy ; alpha1-acid glycoprotein ; labour ; free fatty acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Preliminary studies of the ultrafiltration method for measuring the extent of plasma protein binding of etidocaine showed that etidocaine binding was both pH and concentration dependent. Etidocaine (1 µg/ml) was found to bind avidly to a physiological concentration (74 mg/dl) of α1-acid glycoprotein (α1-AGP) (7.23±0.64%, mean ± SD, unbound). In vitro investigation of etidocaine binding in plasma obtained from blood bank donors and from 19 pregnant women prior to induction of labour, during early labour, mid-labour and delivery showed no difference in etidocaine binding (10.3±3.3%, 7.06±2.66%, 8.15±2.57%, 7.84±3.74% and 9.28±6.06% unbound respectively). There was a significant increase in the mean plasma total free fatty acid (FFA) concentration from pre-labour (0.535±0.240 mM) to delivery (0.948±0.28 mM), while plasma albumin and β-lipoprotein concentrations remained constant. α1-Acid glycoprotein concentration tended to increase slightly from pre-labour to early labour (p〈0.1) but was still within the normal physiological range. There was no correlation between etidocaine binding ratio and the concentrations of FFA or plasma proteins except for a poor correlation with the α1-AGP concentration (r=0.361, p〈0.05). Storage of plasma and inadequate control of plasma pH during ultrafiltration appeared to give spurious binding values. These studies with the extensively bound basic drug etidocaine suggest that unlike many acidic drugs which are bound predominantly to serum albumin, the binding of α1-AGP — bound basic drugs may be unaffected by pregnancy and labour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00542552
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  • 2
    Electronic Resource
    Electronic Resource
    Further studies on the charge-related alterations of methotrexate transport in Ehrlich ascites tumor cells by ionic liposomes: Correlation with liposome-cell association (1982)
    Springer
    The journal of membrane biology 66 (1982), S. 87-95 
    Details
    ISSN: 1432-1424
    Keywords: methotrexate ; liposome ; transport ; Ehrlich ; tumor ; cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Interaction of positively (phosphatidylcholine/stearylamine 5∶1) or negatively (phosphatidylcholine/stearic acid 5∶1) charged liposomes with Ehrlich ascites tumor cells for 1–5 min increases or decreases, respectively, the bidirectional fluxes of the folic acid analog, methotrexate. These effects on influx and efflux appear to be symmetrical since the liposomes do not change the intracellular level of methotrexate at the steady state. Influx kinetics show that these alterations result from an increase or decrease in theV max with no change in theK m in . These effects appear to be specific for the methotrexate-tetrahydrofolate carrier system since the transport of other compounds which utilize this carrier, aminopterin, 5-methyltetrahydrofolate, and 5-formyltetrahydrofolate, is affected similarly to methotrexate, whereas, the transport of folic acid, a compound similar in structure and charge but not significantly transported by this carrier is unaffected by liposomes. Once cells are exposed to charged liposomes, the effects on methotrexate transport cannot be reversed by washing the cells free of the extracellular liposomes. If, however, cells are exposed to liposomes of one charge, washed and then exposed to liposomes of the opposite charge, methotrexate influx is reversed to control rates. The effects of charged liposomes on methotrexate influx were not abolished by treating the cells with neuraminidase, metabolic inhibitors or lowering the temperature to 4°C. Studies on the uptake of [14C] liposomes show that these effects are not proportional to the total amount of lipid associated with the cell but result from an initial rapid liposome-cell association that is not dependent on temperature or energy metabolism nor related to cell surface charge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01868485
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  • 3
    Electronic Resource
    Electronic Resource
    Pharmacokinetics and bioavailability of intravenous, oral, and rectal nitrazepam in humans (1982)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 10 (1982), S. 231-245 
    Details
    ISSN: 1573-8744
    Keywords: nitrazepam ; i.v. ; oral ; rectal administration ; protein binding ; pharmacokinetics ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics and bioavailability of nitrazepam following intravenous, oral (tablet), and rectal (solution) administration were studied in seven healthy, young male volunteers. Nitrazepam plasma concentrations were determined by electron-capture GLC; pharmacokinetic evaluations were made by compartmental analysis (NONLIN) and compared with the results obtained by a less stringent modelling of the data. The plasma concentration-time profile was similar for all three routes of administration. Mean kinetic parameters as obtained by compartmental analysis of i.v. nitrazepam were: distribution half-life 17 min; volume of distribution after equilibrium 2.14 liters/kg; total plasma clearance 61.6 ml/min; elimination half-life 29.0 h. The mean protein unbound fraction of nitrazepam in plasma was 12.3% and the clearance of the unbound fraction was 506 ml/min. Absorption of oral nitrazepam started after the elapse of a lag time (mean value 12 min) and occurred as an apparent first-order process in all but one subject, with a mean absorption half-life of 16 min. Distribution and elimination half-lives were comparable with those following i.v. administration. Following rectal administration of the nitrazepam solution, rapid first-order absorption occurred with a mean lag time of 4 min and a mean absorption half-life of 9 min. Peak times (median 18 min) were significantly shorter than following oral administration (median 38 min), but there was little difference in peak concentrations. The distribution half-life was similar to i.v. and oral administration, but the elimination half-lives were longer with a mean value of 33.1 h. Following i.v. administration a good agreement was found between the results obtained by compartmental analysis using NONLIN and those obtained by a less stringent modelling of the data. Following oral and rectal administration, a good agreement between the two procedures was found for the elimination half-life; estimation of bioavailability, however, was higher by compartmental analysis. The mean bioavailability data showed that absorption is complete when nitrazepam is given orally and almost 20% lower when it is given rectally, but considerable interindividual differences were observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059259
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  • 4
    Electronic Resource
    Electronic Resource
    Disposition of sulfadimethoxine in swine: Inclusion of protein binding factors in a pharmacokinetic model (1982)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 10 (1982), S. 539-550 
    Details
    ISSN: 1573-8744
    Keywords: Sulfadimethoxine ; swine ; pharmacokinetic modelling ; protein binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Sulfadimethoxine was administered intravenously and orally to five swine. More than 75% of the dose was excreted into urine as the acetyl metabolite with 4–6% excreted unchanged. Plasma and urine data were not consistent when a linear pharmacokinetic model was used to describe the data. Sulfadimethoxine has a high affinity for plasma protein, and the data were subsequently fitted to a nonlinear model, which included saturable protein binding. The choice of a nonlinear model was further supported by a minimum value for the Akaike information criteria. The protein binding constant obtained was 2.8× 104 M−1 and the total protein binding site concentration in plasma was 4.6×10−4 m. Both values are comparable with in vitrodata. This result suggests that the nonlinear model involving protein binding can be successfully applied to pharmacokinetic data. The apparent biological half-life of Sulfadimethoxine (free and bound) in plasma was 14 hr; however, the half-life of elimination of free drug was 1.25 hr. Following oral administration, all of the dose was absorbed with an apparent absorption half-life of 2.9 hr.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059036
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  • 5
    Electronic Resource
    Electronic Resource
    The influence of blood collection technique on serum and plasma protein binding of disopyramide (1982)
    Springer
    European journal of clinical pharmacology 22 (1982), S. 185-189 
    Details
    ISSN: 1432-1041
    Keywords: disopyramide ; protein binding ; vacutainer® ; alpha-1-acid-glycoprotein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Serum and plasma disopyramide (D) protein binding was compared after blood was collected from four normal subjects in various Vacutainer® tubes. The fraction of disopyramide bound to proteins in control serum and plasma was drug concentration dependent and correlated well with the capacity factor (N) associated with a high affinity protein binding site. D free fraction increased 60% at a post-equilibrium concentration of 2 µg/ml in plasma following exposure of blood to green-top Vacutainer® stoppers due to a 60% reduction in the affinity constant associated with the high affinity protein binding site. Heparin and EDTA had no effect on the plasma protein binding of D. These results suggest a competitive inhibition of disopyramide binding to α1-acid-glycoprotein following contact of blood with rubber Vacutainer® stoppers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00542466
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  • 6
    Electronic Resource
    Electronic Resource
    The effect of sulphinpyrazone on oxidative drug metabolism in man: Inhibition of tolbutamide elimination (1982)
    Springer
    European journal of clinical pharmacology 22 (1982), S. 321-326 
    Details
    ISSN: 1432-1041
    Keywords: sulphinpyrazone ; tolbutamide ; drug metabolism ; drug interaction ; protein binding ; elimination of tolbutamide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of sulphinpyrazone on tolbutamide elimination was investigated in 6 healthy male volunteers. Co-administration of sulphinpyrazone (200 mg, 6 hourly) reduced mean plasma tolbutamide clearance by 40% and prolonged mean tolbutamide half-life by 80%. Twenty four hours after the cessation of a one week period of chronic sulphinpyrazone therapy tolbutamide plasma clearance (30% reduction) and half-life (19% prolongation) were still significantly different to control values, even though sulphinpyrazone could not be detected in the plasma of any of the subjects at this time. In vitro studies of the plasma protein binding of tolbutamide demonstrated concentration dependent binding but displacement of tolbutamide by sulphinpyrazone in vitro only became apparent at high concentrations of added sulphinpyrazone. Although the concentration dependence of tolbutamide protein binding demonstrated in vitro was also observed in the subject plasma samples, the magnitude of this effect was small. It is concluded that sulphinpyrazone and its metabolite(s) decrease the plasma clearance of tolbutamide by inhibition of oxidative metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00548400
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  • 7
    Electronic Resource
    Electronic Resource
    Interaction of sulphinpyrazone with warfarin (1982)
    Springer
    European journal of clinical pharmacology 22 (1982), S. 327-331 
    Details
    ISSN: 1432-1041
    Keywords: Sulphinpyrazone ; warfarin ; drug metabolism ; drug interaction ; protein binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of sulphinpyrazone administration on the anticoagulant response was investigated in five patients receiving long-term treatment with warfarin. Sulphinpyrazone caused a rapid increase in prothrombin (PT) ratio in all five patients and warfarin dose had to be reduced by a mean of 46% to maintain the PT ratio in the therapeutic range. PT ratio and daily warfarin requirement returned to previous levels when sulphinpyrazone was ceased. Warfarin protein binding was not altered during sulphinpyrazone administration and sulphinpyrazone added to plasma in vitro did not increase warfarin free fraction. The average racemic plasma warfarin concentration over a dosage interval when adjusted for warfarin dose was not altered by sulphinpyrazone administration. The most likely mechanism for this drug interaction is a stereoselective effect of sulphinpyrazone on the metabolism of the warfarin enantiomers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00548401
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  • 8
    Electronic Resource
    Electronic Resource
    Structure-activity relationships in sex attractants for north American noctuid moths (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 731-754 
    Details
    ISSN: 1573-1561
    Keywords: Alkenylcompounds ; pheromones ; chemotaxonomy ; decenyl dodecenyl ; tetradecenyl ; hexadecenyl ; trapping ; Lepidoptera ; Noctuidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Sex attractants known for 145 species of noctuid moths have many common features both as to chemical constituents and to their relationships in blends. The great majority of constituents are straight-chain (Z)-alkenols, -alkenals, or -alkenyl acetates of even carbon number (10 through 16). The unsaturation is nonterminal in odd-numbered positions (5 through 11). In effective lures, these components are blended in specific ratios and the components in a sex pheromone or sex attractant blend are structurally related by “one-change” steps. This means that any blend component differs from one or more other components by a single structural alteration, such as a change in double bond position, or a change in carbon chain length, or a change in the oxygen function. For the few multicomponent systems known in detail, the central place in the “one-change” framework is occupied by the predominant blend component. Different patterns of occurrence of lure components occur in the subfamilies Acronictinae, Noctuinae, Hadeninae, Cuculliinae, Amphipyrinae, Heliothidinae, Plusiinae, Acontiinae, and Pantheinae, and some subfamilies are as yet without known lures. Some guiding principles for elucidation of blend compositions for unstudied species are presented; these guidelines can also be used in improvement of some synthetic blends of unsatisfactory quality.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00988315
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  • 9
    Electronic Resource
    Electronic Resource
    An analysis of total phosphorus transport in river systems (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 241-252 
    Details
    ISSN: 1573-5117
    Keywords: pollution ; rivers ; transport ; calculation ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Human activities generate many pollutants from different land uses. These pollutants include nutrients (e.g., phosphorus and nitrogen), toxic substances (e.g., heavy metals and pesticides), and other substances (e.g., chlorides and salts). These materials often enter a river at some upstream point and are transported downstream by the flowing water. Many substances are transported both during storms and during normal river flow and often the major portion of the transport occurs during the storms. This paper considers the quantification of transport primarily during storms. First, the characteristics of storm transport are discussed. Then, a calculation method for estimating the distance of travel for sediment related materials is presented. Third, a technique to estimate the amount of a given chemical passing a point in a stream over a specified period of time is presented. The last part of this paper contains a technique for tracing the movement of substances through a river network. In particular, this procedure yields information as to the source of given pollutants over the entire Storm period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02391941
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  • 10
    Electronic Resource
    Electronic Resource
    Isolation and properties of Ca2+-transporting glycoprotein and peptide from beef heart mitochondria (1982)
    Springer
    Journal of bioenergetics and biomembranes 14 (1982), S. 213-225 
    Details
    ISSN: 1573-6881
    Keywords: Mitochondria ; transport ; calcium ; bilayer lipid membrane ; channel ; Ca2+-transporting glycoprotein ; peptide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract The 40,000-dalton glycoprotein and 2000-dalton peptide inducing selective Ca2+-transport through bilayer lipid membranes were isolated from beef heart homogenate and mitochondria. Micromolar concentrations of these substances were found to increase the conductivity of membranes by 3–4 orders. Transmembrane Ca2+ gradient induces an electric potential difference whose magnitude is close to the theoretical for ideal Ca2+ selectivity. The inhibitor of mitochondrial Ca2+ transport, ruthenium red, abolishes both the glycoprotein-and peptide-induced Ca2+ transport in bilayer lipid membranes. Thiol groups essential for Ca2+ transport activity were revealed in the glycoprotein and peptide. Addition of these substances to rat liver mitochondria induces Ca2+-dependent inhibition of the state 3 respiration that can be released by uncouplers (oligomycin-like effect).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00751016
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