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  • Chemistry  (3)
  • healthy volunteers  (2)
  • 25.70.−z  (1)
  • Adverse events; critical limits  (1)
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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 47 (1995), S. 417-421 
    ISSN: 1432-1041
    Schlagwort(e): Phase I trials ; Alanine amino transferase ; healthy volunteers ; adverse experience ; normal range ; liver function test
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Abstract In Phase I clinical studies, the maximum tolerated dose has to be determined by a case by case analysis sometimes using a laboratory adverse effect, e.g. an increase in alanine amino transferase (ALT). For this reason a threshold to discriminate between significant or non significant adverse changes in ALT is required particularly in Phase I studies, in order to deal with the very common “close to the limit values”. Previous methods (limit of normal range or normal range plus an arbitrary margin) do not solve this problem. The authors propose a new method taking into account the threshold used as inclusion criteria for ALT (R) and the range of spontaneous variations measured under identical Phase I study conditions (V). The (R) and (V) thresholds, respectively, are defined as 50 IU·1−1 and a 50% increase, from baseline. Thus an ALT value is recognized as a “significant adverse experience” if it exceeds 50 IU·1−1 above an increase from baseline exceeding 50% of the baseline value. To highlight the value of the method, it was implemented in a one year period including 8 studies and 134 subjects. The sensitivity, specificity and positive predictive value of various methods were compared. The results showed the following: Six out of 134 subjects had significant adverse changes in ALT (4%); and all these 6 subjects were detected by the proposed new method without error. Eight subjects including two false positives, were detected by an use of the normal range limit, and only 4 were detected using, the 10% margin. Thus, use of the new method showed 1. keeping the normal range limit as the detection threshold led to preserved sensitivity; 2. it reduced the background noise of false positive results related to chance variation around the upper limit, mainly in subjects with a baseline value close to the limit; 3. it allowed better judgment of the significance of a value which lay just beyond the limit when variation from the baseline exceeding the normal range. The new method produced the best combination of sensitivity, specificity and positive predictive value. Given the small number of subjects in the study, further evaluation with a larger population is required. Finally, the proposed new method seems to be a tool easy to use determining the significance of adverse changes in ALT when the values are close to the limit that is common in Phase I studies.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 52 (1997), S. 81-86 
    ISSN: 1432-1041
    Schlagwort(e): Key words Phase I study ; Adverse events; critical limits ; drug developments
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Abstract Objective: The first goal of phase I drug development is the determination of maximal tolerated dose, which must be established by case-by-case analysis, sometimes using a laboratory adverse event. Since no accurate rule defining lab adverse events, has been validated yet, we propose a new “combined method” based on combination of two thresholds: inclusion values and magnitude of variation. Using this combined method, the label “lab adverse event” is applied if any lab value exceeds the inclusion threshold and is associated with a variation from baseline exceeding the variation threshold defined from reference change limit. Thus, this study aimed to test this combined method on a large healthy volunteer population, studied in 19 phase I centres worldwide, and on five lab parameters: alanine amino transferase, aspartate amino transferase, alkaline phosphatases, creatinine and polymorphonuclear leukocytes. Methods: The inclusion threshold from each center was used. Reference change limits were defined from volunteers previously included in comparable studies and were expressed as absolute values: increases of 10 IU · l−1 for alanine amino transferase or aspartate amino transferase, 15 IU · l−1 for alkaline phosphatases, 15 μmol · l−1 for creatinine and a 0.34 109 · l−1 decrease for polymorphonuclear leukocytes. Comparison between the “combined method” and a normal range method was made using positive predictive value and a ratio between relevant and irrelevant results. This application was implemented in all young healthy volunteers (1134) included in 38 phase I studies sponsored by Rhône Poulenc Rorer from 1991 to 1993. Results: Seventy seven subjects (6.7%) were indicated in final study reports as having a lab adverse event (reference group). Of 179 subjects with lab abnormalities defined by the normal range method, 77 belonged to the reference group, inducing a poor 0.43 positive predictive value. Of ninety subjects with lab adverse events defined by the “combined method”, seventy-five belonged to the reference group, inducing a two-fold higher 0.83 positive predictive value. The combined method produced a high ratio of relevant/irrelevant results ( ) compared with the low ratio ( ) achieved using the normal range method. Conclusion: This new “combined method”, leading to a better definition of lab adverse event, seems an accurate and useful tool for routine case-by-case analysis within phase I drug development studies.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 42 (1992), S. 389-393 
    ISSN: 1432-1041
    Schlagwort(e): Adverse events ; Phase I studies ; healthy volunteers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary All the clinical, laboratory and electrocardiographic adverse events detected during 24 Phase I studies in the same unit over a 5 y period are reported here. 430 healthy male volunteers were involved, corresponding to 5488 days of follow-up. The overall incidence of adverse events was 13.5%, with a significant difference between active drug (15.3%) and placebo (7.4%) treatments. There were 69 distinct types of adverse events. Headache was the most frequent symptom (2%). There were severe adverse events in 20 cases (0.36%), with an incidence of 20/430 per subject (4.6%). There were no deaths or life-threatening events. Although the main objective of Phase I studies is to determine the maximum dose tolerated, cause-effect relationships with adverse events are hard to establish, because of the frequency of adverse events with placebo, and because of the limited number of subjects included such studies.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    ISSN: 1434-601X
    Schlagwort(e): 25.70.−z ; 25.90.+k
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract Low energyπ + andπ − production cross sections have been measured in16O at 65 MeV/u and84Kr at 60 MeV/u induced reactions on7Li,12C,27Al,108Ag and197Au. The results are compared with a previous measurement obtained with16O at 93 MeV/u. Large deviations are observed between light and heavy ion data. At variance with16O, the ratiosπ −/π + are independent of the target in the Krypton case. A change in the regime of the projectile-target mass scaling of cross-sections is observed with the heaviest projectile.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 30 (1992), S. 1419-1421 
    ISSN: 0887-6266
    Schlagwort(e): nuclear magnetic resonance (NMR) with deuterium probe in anisotropically swollen rubbers ; rubbery polymers, anisotropically swollen deuterium NMR study of order in ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 23 (1992), S. 385-389 
    ISSN: 0377-0486
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Raman spectroscopy was used to investigate the kinetics of the free-radical polymerization of methyl methacrylate in toluene, initiated with azobisisobutyronitrile at 70°C. The decrease in the intensity of the 1636 cm-1 C=C stretching band compared with a solvent band as an internal standard allows an accurate determination of the rate of conversion of monomers to polymeric chains. A careful quantitative study of the evolution of the C=O stretch band profile, interpreted in terms of intra-chain dipole-dipole interactions, gives a similar dependence for the conversion.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 25 (1994), S. 313-315 
    ISSN: 0377-0486
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Measurements of the low-frequency Raman spectra (LFRS) (below 100 cm-1) of poly(methyl methacrylates) in solution are reported. The reduced intensity exhibits a power law dependence on the frequency at any concentration and at any conversion rate of the polymerization reaction. Even monomeric liquids such as toluene and methyl methacrylate show such a power law behaviour. The results are compared with recent theories on low-frequency Raman scattering from fractal structures and suggest that a more careful interpretation of LFRS is needed.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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