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ANALYSIS OF RISK FROM EXPOSURE TO ALDICARB USING IMMUNE RESPONSE OF NONUNIFORM POPULATIONS OF MICE
Citation:
Shirazi, M., B. Erickson, R. Hinsdill, AND J. Wymann. ANALYSIS OF RISK FROM EXPOSURE TO ALDICARB USING IMMUNE RESPONSE OF NONUNIFORM POPULATIONS OF MICE. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-90/191 (NTIS PB91116756).
Description:
The immunomodulation response of mice to low levels of aldicarb in drinking water was investigated in four series of studies. he splenic plaque forming cell (PFC) response to red sheep cells were measured for treatment levels of 0.01 to 1000 ppb (ug/kg). ased on their beginning and body weights, the animal populations were uniform in all series of tests, but based on their net body weights and PFC counts they were highly nonuniform in the 30 to 60 day tests and uniform in the 90 and 180 day tests. he mean PVC counts for animals in each treatment were calculated and compared with the mean PFC counts for animals in the controls in all four series of tests. his approach ignores the variabiLity and nonuniformity in the animal population. he outcomes using this approach were stimulatory for the 30 and 60 day tests and inhibitory for the 90 and 180 day tests. n alternative approach was developed based on the analysis of the distributions of the relative are counts of each animal in a treatment with each animal in a control, and specifically addresses the variability and nonuniformity in animal population as integral parts of the analysis. he distribution peaks were estimated by maximum likelihood and kernel/bootstrap procedures and were used to summarize the tests. he outcomes were consistentLy inhibitory, indicating immune suppression. he outcome of this approach converged to the outcome of the mean PFC approach for the 90 and 180 day tests where the animal populations were uniform.