Genetic bioassay

Ohnishi, Y. Kinouchi, T. Manabe, Y. Tsutsui, H. Otsuka, H. Tokiwa, H. Otofuji, T. In "Short-Term Genetic Bioassays in the Evaluation of Complex Environmental Mixtures" Water, M.D., Ed. Plenum New York, in press. 

EVALUATION OF MOTOR VEHICLE AND OTHER COMBUSTION EMISSIONS USING SHORT-TERM GENETIC BIOASSAYS... 

Genetic Bioassay Branchy Genetic Toxicology Division Health Effects Research Laboratory U.S Environmental Protection Agency, Research Triangle Park, NC 27711 U.S.A. 

The development of short-term genetic bioassays has provided relatively simple, sensitive, and rapid bioassays for mutagenic and potential carcinogenic activity. Short-term genetic bioassays have been particularly useful in evaluating combustion emissions This paper summarizes the results of studies where short-term genetic bioassays have been used in the following areas ... 

There are many uncertainties in the use of bioassay methods, not the least of these being the genetic stability of the assay organisms. Stock cultures cannot be treated like chemical reagents, to be put back on the shelf and forgotten between analytical runs. This is an area of analysis best left to the microbiologists if the information is absolutely necessary, the maintenance of cultures and the actual assay should not be left solely in the hands analytical chemists. 

Evolution of chemical defenses according to the optimal defense theory presumes, in addition to costly defenses, that there is genetic variation for the defensive metabolites, that herbivory is the major selective agent for such metabolites, and that the chemical trait in question is efficient in reducing herbivory (Stamp 2003). Research on macroalgal chemical defenses has strongly emphasized the last precondition, which has mainly been studied by testing the deterrence effects of secondary metabolites in bioassays. The defensive role for the trait has been assumed on the basis of deterrence it provides. Veiy little research on the first two... 

Blood-Coagulation Factor VIII Genetics, Physiological Control, and Bioassay G. I. C. Ingram... 

Figure 2 represented a log-probit plot of the observed inhibition of purified bovine erythrocyte acetylcholinesterase as a function of concentration for several of the transformation products of aminocarb. The observation that these inhibition curves are parallel suggests a similar mechanism of interaction for the various derivatives. The parameter I5f. (the concentration of inhibitor required to achieve 50% inhibition oi the enzyme activity) for each of the inhibitors were calculated and are recorded in Table 1. These values are reported relative to the parent compound aminocarb = 1. Also included in Table 1 are the relative toxicities of several of these products to house crickets (Acheta domesticus). It had been our intention to develop bioassay tests using the target insect itself, the eastern spruce budworm (Choristoneura fumiferana). However, spray tower results were quite variable and it was considered that genetic variability of the stock culture made the production of uniform test batches difficult to achieve. Using the house crickets, an LD q of 130-155 ppm for aminocarb standard was observed over the course of more than 25 bioassays. Also included in Table 1 are observations by Abdel-Wahab and Casida (19) using human plasma or house fly head cholinesterases. 

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