Search Results - (Author, Cooperation:J. Tyrer)

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  1. 1
    J. R. Perry ; F. Day ; C. E. Elks ; P. Sulem ; D. J. Thompson ; T. Ferreira ; C. He ; D. I. Chasman ; T. Esko ; G. Thorleifsson ; E. Albrecht ; W. Q. Ang ; T. Corre ; D. L. Cousminer ; B. Feenstra ; N. Franceschini ; A. Ganna ; A. D. Johnson ; S. Kjellqvist ; K. L. Lunetta ; G. McMahon ; I. M. Nolte ; L. Paternoster ; E. Porcu ; A. V. Smith ; L. Stolk ; A. Teumer ; N. Tsernikova ; E. Tikkanen ; S. Ulivi ; E. K. Wagner ; N. Amin ; L. J. Bierut ; E. M. Byrne ; J. J. Hottenga ; D. L. Koller ; M. Mangino ; T. H. Pers ; L. M. Yerges-Armstrong ; J. Hua Zhao ; I. L. Andrulis ; H. Anton-Culver ; F. Atsma ; S. Bandinelli ; M. W. Beckmann ; J. Benitez ; C. Blomqvist ; S. E. Bojesen ; M. K. Bolla ; B. Bonanni ; H. Brauch ; H. Brenner ; J. E. Buring ; J. Chang-Claude ; S. Chanock ; J. Chen ; G. Chenevix-Trench ; J. M. Collee ; F. J. Couch ; D. Couper ; A. D. Coviello ; A. Cox ; K. Czene ; P. D'Adamo A ; G. Davey Smith ; I. De Vivo ; E. W. Demerath ; J. Dennis ; P. Devilee ; A. K. Dieffenbach ; A. M. Dunning ; G. Eiriksdottir ; J. G. Eriksson ; P. A. Fasching ; L. Ferrucci ; D. Flesch-Janys ; H. Flyger ; T. Foroud ; L. Franke ; M. E. Garcia ; M. Garcia-Closas ; F. Geller ; E. E. de Geus ; G. G. Giles ; D. F. Gudbjartsson ; V. Gudnason ; P. Guenel ; S. Guo ; P. Hall ; U. Hamann ; R. Haring ; C. A. Hartman ; A. C. Heath ; A. Hofman ; M. J. Hooning ; J. L. Hopper ; F. B. Hu ; D. J. Hunter ; D. Karasik ; D. P. Kiel ; J. A. Knight ; V. M. Kosma ; Z. Kutalik ; S. Lai ; D. Lambrechts ; A. Lindblom ; R. Magi ; P. K. Magnusson ; A. Mannermaa ; N. G. Martin ; G. Masson ; P. F. McArdle ; W. L. McArdle ; M. Melbye ; K. Michailidou ; E. Mihailov ; L. Milani ; R. L. Milne ; H. Nevanlinna ; P. Neven ; E. A. Nohr ; A. J. Oldehinkel ; B. A. Oostra ; A. Palotie ; M. Peacock ; N. L. Pedersen ; P. Peterlongo ; J. Peto ; P. D. Pharoah ; D. S. Postma ; A. Pouta ; K. Pylkas ; P. Radice ; S. Ring ; F. Rivadeneira ; A. Robino ; L. M. Rose ; A. Rudolph ; V. Salomaa ; S. Sanna ; D. Schlessinger ; M. K. Schmidt ; M. C. Southey ; U. Sovio ; M. J. Stampfer ; D. Stockl ; A. M. Storniolo ; N. J. Timpson ; J. Tyrer ; J. A. Visser ; P. Vollenweider ; H. Volzke ; G. Waeber ; M. Waldenberger ; H. Wallaschofski ; Q. Wang ; G. Willemsen ; R. Winqvist ; B. H. Wolffenbuttel ; M. J. Wright ; D. I. Boomsma ; M. J. Econs ; K. T. Khaw ; R. J. Loos ; M. I. McCarthy ; G. W. Montgomery ; J. P. Rice ; E. A. Streeten ; U. Thorsteinsdottir ; C. M. van Duijn ; B. Z. Alizadeh ; S. Bergmann ; E. Boerwinkle ; H. A. Boyd ; L. Crisponi ; P. Gasparini ; C. Gieger ; T. B. Harris ; E. Ingelsson ; M. R. Jarvelin ; P. Kraft ; D. Lawlor ; A. Metspalu ; C. E. Pennell ; P. M. Ridker ; H. Snieder ; T. I. Sorensen ; T. D. Spector ; D. P. Strachan ; A. G. Uitterlinden ; N. J. Wareham ; E. Widen ; M. Zygmunt ; A. Murray ; D. F. Easton ; K. Stefansson ; J. M. Murabito ; K. K. Ong
    Nature Publishing Group (NPG)
    Published 2014
    Staff View
    Publication Date:
    2014-09-19
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Adolescent ; Age Factors ; *Alleles ; Body Mass Index ; Breast Neoplasms/genetics ; Cardiovascular Diseases/genetics ; Child ; Diabetes Mellitus, Type 2/genetics ; Europe/ethnology ; Female ; Genetic Loci/*genetics ; Genome-Wide Association Study ; Genomic Imprinting/genetics ; Humans ; Hypothalamo-Hypophyseal System/physiology ; Intercellular Signaling Peptides and Proteins/genetics ; Male ; Membrane Proteins/genetics ; Menarche/*genetics ; Obesity/genetics ; Ovary/physiology ; *Parents ; Polymorphism, Single Nucleotide/genetics ; Potassium Channels, Tandem Pore Domain/genetics ; Proteins/genetics ; Quantitative Trait Loci/genetics ; Receptors, GABA-B/metabolism ; Receptors, Retinoic Acid/metabolism ; Ribonucleoproteins/genetics
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  2. 2
    J. Yang ; R. J. Loos ; J. E. Powell ; S. E. Medland ; E. K. Speliotes ; D. I. Chasman ; L. M. Rose ; G. Thorleifsson ; V. Steinthorsdottir ; R. Magi ; L. Waite ; A. V. Smith ; L. M. Yerges-Armstrong ; K. L. Monda ; D. Hadley ; A. Mahajan ; G. Li ; K. Kapur ; V. Vitart ; J. E. Huffman ; S. R. Wang ; C. Palmer ; T. Esko ; K. Fischer ; J. H. Zhao ; A. Demirkan ; A. Isaacs ; M. F. Feitosa ; J. Luan ; N. L. Heard-Costa ; C. White ; A. U. Jackson ; M. Preuss ; A. Ziegler ; J. Eriksson ; Z. Kutalik ; F. Frau ; I. M. Nolte ; J. V. Van Vliet-Ostaptchouk ; J. J. Hottenga ; K. B. Jacobs ; N. Verweij ; A. Goel ; C. Medina-Gomez ; K. Estrada ; J. L. Bragg-Gresham ; S. Sanna ; C. Sidore ; J. Tyrer ; A. Teumer ; I. Prokopenko ; M. Mangino ; C. M. Lindgren ; T. L. Assimes ; A. R. Shuldiner ; J. Hui ; J. P. Beilby ; W. L. McArdle ; P. Hall ; T. Haritunians ; L. Zgaga ; I. Kolcic ; O. Polasek ; T. Zemunik ; B. A. Oostra ; M. J. Junttila ; H. Gronberg ; S. Schreiber ; A. Peters ; A. A. Hicks ; J. Stephens ; N. S. Foad ; J. Laitinen ; A. Pouta ; M. Kaakinen ; G. Willemsen ; J. M. Vink ; S. H. Wild ; G. Navis ; F. W. Asselbergs ; G. Homuth ; U. John ; C. Iribarren ; T. Harris ; L. Launer ; V. Gudnason ; J. R. O'Connell ; E. Boerwinkle ; G. Cadby ; L. J. Palmer ; A. L. James ; A. W. Musk ; E. Ingelsson ; B. M. Psaty ; J. S. Beckmann ; G. Waeber ; P. Vollenweider ; C. Hayward ; A. F. Wright ; I. Rudan ; L. C. Groop ; A. Metspalu ; K. T. Khaw ; C. M. van Duijn ; I. B. Borecki ; M. A. Province ; N. J. Wareham ; J. C. Tardif ; H. V. Huikuri ; L. A. Cupples ; L. D. Atwood ; C. S. Fox ; M. Boehnke ; F. S. Collins ; K. L. Mohlke ; J. Erdmann ; H. Schunkert ; C. Hengstenberg ; K. Stark ; M. Lorentzon ; C. Ohlsson ; D. Cusi ; J. A. Staessen ; M. M. Van der Klauw ; P. P. Pramstaller ; S. Kathiresan ; J. D. Jolley ; S. Ripatti ; M. R. Jarvelin ; E. J. de Geus ; D. I. Boomsma ; B. Penninx ; J. F. Wilson ; H. Campbell ; S. J. Chanock ; P. van der Harst ; A. Hamsten ; H. Watkins ; A. Hofman ; J. C. Witteman ; M. C. Zillikens ; A. G. Uitterlinden ; F. Rivadeneira ; L. A. Kiemeney ; S. H. Vermeulen ; G. R. Abecasis ; D. Schlessinger ; S. Schipf ; M. Stumvoll ; A. Tonjes ; T. D. Spector ; K. E. North ; G. Lettre ; M. I. McCarthy ; S. I. Berndt ; A. C. Heath ; P. A. Madden ; D. R. Nyholt ; G. W. Montgomery ; N. G. Martin ; B. McKnight ; D. P. Strachan ; W. G. Hill ; H. Snieder ; P. M. Ridker ; U. Thorsteinsdottir ; K. Stefansson ; T. M. Frayling ; J. N. Hirschhorn ; M. E. Goddard ; P. M. Visscher
    Nature Publishing Group (NPG)
    Published 2012
    Staff View
    Publication Date:
    2012-09-18
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Body Height/genetics ; *Body Mass Index ; Co-Repressor Proteins ; Female ; *Genetic Variation ; Genome-Wide Association Study ; Humans ; Male ; Nerve Tissue Proteins/genetics ; *Phenotype ; Polymorphism, Single Nucleotide ; Proteins/*genetics ; Repressor Proteins/genetics
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  3. 3
    Smith, G. A. ; Hooper, W. D. ; Tyrer, J. H. ; Eadie, M. J. ; Werth, B.

    Oxford, UK : Blackwell Publishing Ltd
    Published 1979
    Staff View
    ISSN:
    1440-1681
    Source:
    Blackwell Publishing Journal Backfiles 1879-2005
    Topics:
    Medicine
    Notes:
    1. The bioavailabilities of carbamazepine in 100 mg and 200 mg tablets have been compared in a cross-over study of six subjects after two 600 mg doses of the drug, the different preparations being taken at 3 week intervals.2. Areas under the plasma level curves, absorption rate constants and times to achieve peak plasma levels showed little difference between the two preparations. These findings suggest similar rates and extents of bioavailability of carbamazepine in the two preparations.3. Calculated mean absorption and elimination parameters for carbamazepine were as follows: kabδ= 0.1081 h-1, (s.d. = 0.0289); Tmax= 23.39 h, (s.d. = 8.66); K: = 0.0191 h-1, (s.d. = 0.0033); VD= 0.989 1/kg, (s.d. = 0.159); and clearance = 0.0185 1/kgh, (s.d. = 0.0015).
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  4. 4
    Eadie, M. J. ; Tyrer, J. H. ; Bochner, F. ; Hooper, W. D.

    Oxford, UK : Blackwell Publishing Ltd
    Published 1976
    Staff View
    ISSN:
    1440-1681
    Source:
    Blackwell Publishing Journal Backfiles 1879-2005
    Topics:
    Medicine
    Notes:
    1. Plasma phenytoin (diphenylhydantoin) levels after different drug doses were correlated with urinary 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) excretions in four subjects.2. In three of four subjects the proportion of the phenytoin dose that was excreted as p-HPPH diminished as the dose increased. In the fourth, p-HPPH output remained proportionate to dose of phenytoin until elimination of the drug fell below its input.3. Plasma p-HPPH levels were measured in two subjects; the data suggested that the renal excretion of p-HPPH was not rate-limited.4. In three of four subjects, there was the possibility that alternative pathways for eliminating phenytoin may have developed as drug doses increased and the capacity for forming p-HPPH became saturated.5. Overall phenytoin elimination appeared to approach saturation at concentrations of the drug encountered therapeutically. When Michaelis-Menten kinetics were applied to data for phenytoin elimination in twenty-one adults and fifteen children, the mean apparent Km value for the adults corresponded to a plasma drug concentration of 5·8 μg/ml, and in the children to 5·3 μg/ml. The mean Vmax values in the two groups were, respectively 8·1 mg/kg per day and 12·5 mg/kg per day.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  5. 5
    Roach, R. J. ; Raymond, E. A. ; Tyrer, J. R. ; Sharp, B. L.
    Springer
    Published 1995
    Staff View
    ISSN:
    1572-817X
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Electrical Engineering, Measurement and Control Technology
    Physics
    Notes:
    Abstract Information presented by other workers on fumes generated during high-power CO2 laser processing tends in most cases to be empirical and qualitative in nature, which has limited the significance of this data to real industrial applications. This paper reviews information on the nature of laser processing fumes and proposes a model for indexing the risk associated with the fumes from both plastics and metal materials processing. The index allows the risks from a specific laser processing system to be assessed and classified into one of three groups. Classification of the risk associated with particular fumes enables appropriate choices about the extraction and filtration system to be made. Application of this model highlights the risks involved in processing stainless steel, owing to the formation of Cr(vi). It also highlights the problems associated with processing Kevlar, polycarbonate, and polyamide.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  6. 6
    Tyrer, J.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0143-8166
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Electrical Engineering, Measurement and Control Technology
    Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Physics
    Technology
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  7. 7
    Tyrer, J.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0143-8166
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Electrical Engineering, Measurement and Control Technology
    Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Physics
    Technology
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  8. 8
    Folkes, J.A. ; Tyrer, J. ; Bandle, A.M.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0143-8166
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Electrical Engineering, Measurement and Control Technology
    Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Physics
    Technology
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  9. 9
    Folkes, J.A. ; Tyrer, J. ; Bandle, A.M.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0143-8166
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Electrical Engineering, Measurement and Control Technology
    Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Physics
    Technology
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  10. 10
    Tyrer, J.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0143-8166
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Electrical Engineering, Measurement and Control Technology
    Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Physics
    Technology
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  11. 11
    Kerr, D. ; Tyrer, J.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0143-8166
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Electrical Engineering, Measurement and Control Technology
    Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Physics
    Technology
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  12. 12
    Tyrer, J. W.

    London : Periodicals Archive Online (PAO)
    Published 1922
    Staff View
    ISSN:
    0022-5185
    Topics:
    Theology and Religious Studies
    Notes:
    NOTES AND STUDIES
    URL:
    Articles: DFG German National Licenses
  13. 13
    Tyrer, J. W.

    London : Periodicals Archive Online (PAO)
    Published 1924
    Staff View
    ISSN:
    0022-5185
    Topics:
    Theology and Religious Studies
    Notes:
    NOTES AND STUDIES
    URL:
    Articles: DFG German National Licenses
  14. 14
  15. 15
    Eadie, M. J. ; Tyrer, J. H. ; Kukums, J. R. ; Hooper, W. D.
    Springer
    Published 1970
    Staff View
    ISSN:
    1432-119X
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Biology
    Medicine
    Notes:
    Summary Uncertainty about the nature of the reduction products of ditetrazolium salts may have limited their use in quantitative histochemistry. Our studies have shown that under appropriate conditions pure Nitro-BT reduces through a red intermediate substance to a stable blue diformazan. Nitrobenzene was found to be a satisfactory solvent for this diformazan. The monotetrazolium INT may also be reduced to a formazan through an intermediate phase. The amounts of definitive formazan produced from both monotetrazolium and ditetrazolium salts may be influenced by the solubility of their intermediate reduction compounds in the systems in which reduction is occurring. The yield of definitive diformazan from Nitro-BT after chemical reduction, and after enzymatic reduction in liver homogenate and sections of a “mock” tissue, was not in linear proportion to the strength of reducing conditions; however, the yields of formazan from the monotetrazoliums INT and MTT were linear. This finding suggests that in quantitative histochemistry it is essential to calibrate reactions involving ditetrazolium reduction.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  16. 16
    Tyrer, J. H. ; Eadie, M. J. ; Kukums, J. R.
    Springer
    Published 1971
    Staff View
    ISSN:
    1432-119X
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Biology
    Medicine
    Notes:
    Summary An investigation has been carried out on the stability of several enzymes in portions of rabbit brain and spinal cord kept at controlled temperatures between 22 and 37° C for periods up to 24 hours before processing for enzyme activity. The enzymes studied were NAD diaphorase, succinate, lactate, glutamate and glucose-6-phosphate dehydrogenases, and monoamine oxidase. One-wavelength “plug” cytophotometric measurements of enzyme activity were carried out on Purkinje cells, neuropil of the granular layer of the cerebellar cortex and on anterior horn cells. Succinate dehydrogenase activity proved to be stable after 24 hours post-mortem exposure at 37°C. Lactate dehydrogenase, NAD diaphorase and monoamine oxidase activities were less stable at the higher temperatures but were stable at 22°C. Glutamate and glucose-6-phosphate dehydrogenase activities fell significantly with exposure at 22°C. It thus appears possible to make valid histochemical measurements of the activities of certain oxidative enzymes in selected post-mortem brain material.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  17. 17
    Staff View
    ISSN:
    1432-1041
    Keywords:
    midazolam ; hypnotic drug ; benzodiazepine ; pharmacokinetics ; aged patients
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Medicine
    Notes:
    Summary The pharmacokinetics of midazolam, an imidazo-benzodiazepine derivative, have been studied in 13 subjects over the age of 60 years who received the drug intravenously (0.07 mg kg−1) as an induction agent for endoscopy. Two to three days later, 6 of these subjects received 5 mg of midazolam intramuscularly, and another 6 of the subjects received 10 mg of the drug orally. The plasma concentration-time curves were again studied pharmacokinetically. After intravenous dosing, the mean (± SD) elimination half-life (2.14±1.24 h) showed a statistically significant trend to increase with age in the subjects older than 60 years. While the mean (± SD) clearance value (0.30±0.19 l kg−1h−1) tended to fall with age in the elderly subjects, this trend was not statistically significant. Apparent volume of distribution did not appear to be related to advancing age beyond 60 years, and this parameter (mean ± SD) did not differ to a statistically significant extent between the aged subjects (0.77±0.47 l kg−1) and the young subjects studied previously (1.09±0.58 l kg−1). Atropine premedication did not appear to alter the dispositional parameters of the intravenously administered drug. Intramuscularly administered midazolam was absorbed rapidly. Bioavailability appeared incomplete (F=0.59±0.15, mean ± SD), possibly due to saturable elimination of the drug at the higher plasma levels which were obtained after intravenous midazolam. Oral bioavailability, relative to intravenous, was 0.34±0.17, (mean ± SD), with an appreciable but variable lag time (0.74±0.40 h, mean ± SD). Orally, in the dose used, the drug was an inefficient hypnotic with four of the six subjects failing to attain the plasma drug level of 44–50 µg l−1, which appeared to be the approximate threshold for sleep. It is impossible to know whether this failure represents an age related effect on drug absorption, or is a consequence of the upper alimentary tract abnormalities for which the endoscopies were done.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  18. 18
    Staff View
    ISSN:
    1432-1041
    Keywords:
    Bioavailability ; carbamazepine ; elimination ; pharmacokinetics
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Medicine
    Notes:
    Summary The time-courses of plasma carbamazepine concentrations were followed in six apparently healthy adult subjects who, at different times, took single oral drug doses of 200, 400, 500, 600, 700, 800 and 900 mg. There were some suggestions of impaired bioavailability of the drug when given in tablet form. The following values were obtained for various pharmacokinetic parameters:k abs =0.176±0.209 h−1;k=0.0203±0.0055 h−1; T1/2=37.5±13.1 h; VD=0.825±0.1041 · kg−1; Clearance=0.0163±0.0061 l · kg−1. The elimination rate constant showed a statistically significant increase with increasing drug dose. This may help explain the clinical observation that the rate of rise of steady state plasma carbamazepine concentrations tends to decrease with dose increase in patients taking carbamazepine alone.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  19. 19
    Staff View
    ISSN:
    1432-1041
    Keywords:
    dexamethasone ; bioavailability ; pharmacokinetics ; ‘first-pass’ effect ; pre-systemic elimination
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Medicine
    Notes:
    Summary The pharmacokinetics and oral biovailability of dexamethasone were studied in 6 patients with neurological disease being treated with high dosages of the drug. A specific high performance liquid chromatographic assay was used to measure dexamethasone concentrations. Unlike the previously published mean figure of 0.78 for the oral bioavailability of the drug given in single doses to healthy volunteers, the mean bioavailability of dexamethasone in the patients studied was 0.53±SD 0.40. It appeared more likely that this incomplete bioavailability was due to presystemic elimination than to poor absorption. The intravenous clearance of the drug was relatively high (0.4902±SD 2291 l kg−1, approximately 65% of expected hepatic plasma flow), the oral clearance higher (2.5804±SD 3.2181 l kg−1 h−1) while the absorption rate constant (4.8729±8.4998 h−1), suggested rapid absorption after oral administration. Prior phenytoin and possibly prior dexamethasone therapy is likely to have contributed to the higher clearance values of the drug in these patients than the values reported in healthy volunteers after single dose studies.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  20. 20
    Staff View
    ISSN:
    1432-1041
    Keywords:
    aspirin ; migraine ; salicylic acid ; metoclopramide ; drug absorption ; pharmacokinetics
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Medicine
    Notes:
    Summary The pharmacokinetics of aspirin (ASA) in acute migraine attacks, and the influence of metoclopramide on ASA disposition, were studied in 32 attacks in 30 patients. An intergroup comparison was made between normal volunteers, and the migraineurs, who were assigned at random to one of three treatment groups: a) oral ASA only (900 mg); b) 10 mg oral metoclopramide + oral ASA 900 mg; c) 10 mg i. m. metoclopramide + oral ASA 900 mg. Plasma ASA and SA levels were measured serially over 2 h, and the resultant data evaluated pharmacokinetically. Metoclopramide plasma levels were also determined over 2 h, and the results compared with a second group of normal volunteers. The rates of oral ASA absorption and elimination were unaffected by migraine. Mean absorption rate constants of 14.15±9.48 h−1 (normals), 7.91±3.42 h−1 (ASA only), 6.74±3.26 h−1 (ASA + oral metoclopramide) and 8.12±2.82 h−1 (ASA + i. m. metoclopramide) were calculated. Mean elimination rate constants ranged from 2.56 h−1 to 3.37 h−1, and did not differ significantly between controls and migrainous patients. Values for absorption lag time, however, were higher in migraine patients treated with ASA alone than in any other group. The amount of ASA absorbed unhydrolysed was also lower in this group. SA levels appeared unaffected either by the migraine attack, or by metoclopramide administration, over the period of study. Metoclopramide plasma levels were significantly lower during migraine attacks, and the amount of drug absorbed up to 2 h from dosing was also reduced, as compared with non-migrainous subjects. It was concluded that acute migraine caused a delay in orally administered ASA reaching its absorption sites, probably as a result of gastric stasis, and may have decreased the amount of ASA absorbed. The prior administration of metoclopramide, either orally or intramuscularly, reduced the absorption lag time, and thus promoted the early absorption of ASA, probably by restoring alimentary tract motility.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses