Genotoxicity testing: Moving beyond qualitative “screen and bin” approach towards characterization of dose-response and thresholds

2010 ◽  
Vol 51 (8-9) ◽  
pp. 792-799 ◽  
Author(s):  
Lynn H. Pottenger ◽  
B. Bhaskar Gollapudi
Keyword(s):  
Dose Response ◽  
Genotoxicity Testing

Characterization of dose-response for count data using a generalized MCP-Mod approach in an adaptive dose-ranging trial

2015 ◽  
Vol 14 (4) ◽  
pp. 359-367 ◽  
Author(s):  
Francois Mercier ◽  
Bjoern Bornkamp ◽  
David Ohlssen ◽  
Erik Wallstroem
Keyword(s):  
Dose Response ◽  
Count Data ◽  
Dose Ranging

Dose response characterization of the association of serum digoxin concentration with mortality outcomes in the Digitalis Investigation Group trial

2016 ◽  
Vol 18 (8) ◽  
pp. 1072-1081 ◽  
Author(s):  
Kirkwood F. Adams ◽  
Javed Butler ◽  
J. Herbert Patterson ◽  
Wendy Gattis Stough ◽  
Jerry L. Bauman ◽  
...  
Keyword(s):  
Dose Response ◽  
Digoxin Concentration ◽  
Serum Digoxin Concentration ◽  
Serum Digoxin ◽  
Group Trial

P1-158: Characterization of the behavioural dose-response of NMDA in 3xTg-AD mice at different stages of the disease and its modulation by early-life stimulation

2010 ◽  
Vol 6 ◽  
pp. S220-S220
Author(s):  
Lydia Gimenez-Llort ◽  
Ismael Alvarez-Monton ◽  
Raquel Baeta-Corral ◽  
Frank M. Laferla
Keyword(s):  
Dose Response ◽  
Early Life

Characterization of Contaminants and Environments

2017 ◽  
Author(s):  
Morton Lippmann ◽  
Richard B. Schlesinger
Keyword(s):  
Health Effects ◽  
Human Activity ◽  
Dose Response ◽  
Chemical Contaminants ◽  
Environmental Media ◽  
Scientific Terminology ◽  
Dynamic Mass ◽  
Energy Transfers ◽  
Structural Aspects

This chapter describes the extensive scientific terminology needed to describe the various classes of chemical contaminants as they occur in environmental media (air, water, soil, etc.) and the structural aspects and dynamic mass and energy transfers within and among the atmosphere, hydrosphere, lithosphere, and biosphere. It also introduces: the characteristics of occupational environments; health effects attributable to occupational and environmental exposures; dose response relationships in populations; and how they are affected by anthropogenic (human activity caused) inputs and disruptions.

Characterization of Selected Common Lambsquarters (Chenopodium album) Biotypes with Tolerance to Glyphosate

Weed Science ◽  
2008 ◽  
Vol 56 (5) ◽  
pp. 685-691 ◽  
Author(s):  
Andrew M. Westhoven ◽  
Greg R. Kruger ◽  
Corey K. Gerber ◽  
Jeff M. Stachler ◽  
Mark M. Loux ◽  
...  
Keyword(s):  
Seed Production ◽  
Dose Response ◽  
Chenopodium Album ◽  
Dry Weight ◽  
Growth Stages ◽  
Flower Primordia ◽  
Common Lambsquarters ◽  
Early Portion ◽  
Dose Response Study

Biotypes of common lambsquarters with tolerance to glyphosate have been identified in a number of states, but little is known about their fitness characteristics. Field and greenhouse studies were conducted to characterize the response of selected glyphosate-tolerant common lambsquarters biotypes to glyphosate, and also their biological and reproductive characteristics. In a greenhouse dose-response study, GR50and GR90values for four tolerant biotypes ranged from 1.48 to 3.22 and 8.73 to 18.7 kg ae ha−1, respectively, compared to 0.57 and 2.39 kg ae ha−1, respectively, for a glyphosate-sensitive biotype. In a field dose-response study, the GR50and GR90values were 0.06 and 0.48 kg ae ha−1, respectively, for a tolerant biotype, compared to 0.036 and 0.19 kg ae ha−1, respectively, for the sensitive biotype. The growth rate, time until flowering, and seed production of eight tolerant and two sensitive biotypes was evaluated in a field study. The tolerant biotypes grew taller, amassed more leaf area and dry weight, and advanced through growth stages more rapidly than sensitive biotypes during the early portion of the growing season. The tolerant biotypes were taller than sensitive biotypes at 6 and 10 wk after transplanting, but had lower dry weight at maturity. Tolerant biotypes initiated flower primordia approximately 6 to 8 wk after transplanting, whereas sensitive biotypes required 12 wk. However, no apparent fitness penalties were observed in glyphosate-tolerant biotypes based on seed-production estimates.

Characterization of sulfidopeptide leukotriene responses in sheep tracheal smooth muscle in vitro

1991 ◽  
Vol 69 (6) ◽  
pp. 805-811 ◽  
Author(s):  
K. Tomioka ◽  
J. T. Jackowski ◽  
W. M. Abraham
Keyword(s):  
Smooth Muscle ◽  
Dose Response ◽  
Tracheal Smooth Muscle ◽  
Response Curves ◽  
Leukotriene Antagonist ◽  
Dose Response Curves ◽  
The Right ◽  
Glutamyl Transpeptidase

We have investigated the effects of leukotrienes (LTs) on isolated tracheal smooth muscle from sheep sensitive to Ascaris suum antigen. LTC4 and LTD4 produced dose-dependent contractions of sheep trachea, but LTE4 was virtually inactive. YM-17690, a non-analogous LT agonist, produced no contractile response up to 100 μM. Indomethacin (5 μM) had no effect on LTC4- and LTD4-induced contractions. L-Serine borate (45 mM), an inhibitor of γ-glutamyl transpeptidase, shifted the dose–response curve of LTC4 to the left by 161-fold, and L-cysteine (6 mM), an inhibitor of aminopeptidase, shifted the dose–response curves of LTC4 and LTD4 to the left by 67- and 23-fold, respectively. YM-16638 (1 μM), an LT antagonist, shifted the dose–response curves of LTC4 and LTD4 to the right with pKB values of 6.57 and 7.13, respectively. YM-16638 did not affect LTC4-induced contractions of L-serine borate-treated tissues, indicating that the compound acts only on LTD4 receptors in sheep trachea. LTE4 (1 μM) shifted the dose–response curves of LTC4 and LTD4 to the right with pKB values of 6.87 and 7.31, respectively. YM-17690 (10 μM) showed effects similar to LTE4, suggesting that the compound acts as an LTE4 agonist in sheep trachea. These results suggest that in sheep tracheal smooth muscle (a) LTC4 and LTD4 produce contractions, (b) these LT-induced contractions are not mediated by cyclooxygenase products, (c) LTC4 is converted to LTD4 and then to LTE4, and (d) the potency of the LTC4- and LTD4-induced contractions is increased when their conversion to LTE4 is inhibited. This potentiation may result from the inability of LTE4 to contract sheep trachea and (or) its antagonist actions.Key words: leukotriene antagonist, receptors, asthma.

Optimization and Characterization of Capture ELISA Methodology for Lp(a) Lipoprotein Quantification

1992 ◽  
Vol 29 (3) ◽  
pp. 275-282 ◽  
Author(s):  
Karl M Doetsch ◽  
Paul S Roheim ◽  
James J Thompson
Keyword(s):  
Monoclonal Antibody ◽  
Alkaline Phosphatase ◽  
Dose Response ◽  
Reaction Conditions ◽  
Elisa System ◽  
Capture Elisa ◽  
Antibody Recognition ◽  
C Storage ◽  
Time Periods

In order to better characterize and optimize a typical capture ELISA system for Lp(a) lipoprotein, we have analysed kinetic details of the reaction. Plate coating with polyclonal antibody, recognition of captured analyte with monoclonal antibody, and detection of monoclonal antibody with alkaline phosphatase-labeled antiglobulin were essentially complete after one hour, probably being driven forward by a relative excess of reagent. However, complete capture of the Lp(a) analyte required about 6 h at low input concentrations. Shorter time periods for capture might therefore result in decreased sensitivity and reproducibility. Deviations from linearity in the assay dose response were associated with incomplete capture of Lp(a) and significant depletion of the monoclonal recognition antibody. With the final reaction conditions described, no significant differences in immunochemical reactivity between samples were found by analysis of dose response slopes. Finally, interferences from plasminogen, −20°C storage, anticoagulants, LDL, haemolysis, and bilirubin were minimal.

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