Statistical interpretation of results of experiments involving unscheduled DNA synthesis is examined from a design standpoint. Most appropriate methods currently in use are evaluated and some modifications and extensions are suggested. Concerns about replication and/or interaction errors are evaluated and methods for their appropriate handling are discussed. It is suggested that methods incorporating both dose-response and heterogeneity statistics should be considered in treating results from unscheduled DNA synthesis experiments. Proper designs for such experiments are emphasized.
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Abbreviations
- ANOVA:
-
analysis of variance
- MSE:
-
mean square error
- UDS:
-
unscheduled DNA synthesis
References
ATAGE, P. (1955). Tests for linear trends in proportions and frequencies. Biometrics 11:375–386.
BMDP Statistical Software (1983). University of California Press, Los Angeles.
BUDROE, J.D., SHADDOCK, J.G. and CASCIANO, D.A. (1984). A study of the potential genotoxicity of methapyrilene and related antihistamines using the hepatocyte/DNA repair assay. Mutation Res. 135:131–137.
CASAGRANDE, J.T., PIKE, M.C. and SMITH, P.G. (1978). The power function of the “exact” test for comparing two binomial distributions. Appl. Statist. 27:176–180.
CASAGRANDE, J.T., PIKE, M.C. and SMITH, P.G. (1981). Algorithm AS129: The power function of the “exact” test for comparing two binomial distributions. Appl. Statist. 27:212–219. [Errata (1980): Appl. Statist. 29:118; Appl. Statist. (1981) 30:108.]
CASCIANO, D.A. (1979). Use of isolated rodent hepatocytes to evaluate potential premutagens and precarcinogens. In: Mammalian Cell Mutagenesis: The Maturation of Test Systems, Banbury Report No. 2 (A.W. Hsie, J.P. O'Neil, and V.R. McElheny, eds.), pp. 125–131. Cold Spring Harbor, New York.
CASCIANO, D.A. and GAYLOR, D.W. (1983). Statistical criteria for evaluating chemicals as positive or negative in the hepatocyte/DNA repair assay. Mutation Res. 122:81–86.
COCHRAN, W.G. (1954). Some methods for strengthening the common X 2 tests. Biometrics 10:417–451.
COHEN, J. (1977). Statistical Power Analysis for the Behavioral Sciences. Academic Press, New York.
CONOVER, W.J. and IMAN, R.L. (1981). Rank transformations as a bridge between parametric and nonparametric statistics. American Statist. 35:124–129.
COC, D.R. (1970). Analysis of Binary Data. Chapman and Hall, London.
DIXON, W.J. and MASSEY, F.J., Jr. (1969). Introduction to Statistical Analysis, pp. 114–119, 3rd Ed. McGraw-Hill, New York.
DUNLAP, W.P. (1982). An interactive FORTRAN IV program for calculating aspects of power with dichotomous data. Behav. Res. Meth. Instr. 14:422–424.
DUNLAP, W. P., MARX, M.S. and AGAMY, G.J. (1981). FORTRAN functions for calculating probabilities associated with Dunnett's test. Behav. Res. Meth. Instr. 13:363–366.
DUNNETT, C. W. (1955). A multiple comparison procedure for comparing several treatments with a control. J. Am. Stat. Assoc. 50:1096–1121.
DUNNETT, C.W. (1964). New tables for multiple comparisons with a control. Biometrics 20:482–491.
DYKE, G.V. and PATTERSON, H.D. (1952). Analysis of factorial arrangements when the data are proportions. Biometrics 8:1–12.
EVERITT, B.S. (1977). The Analysis of Contingency Tables, pp. 80–107. Chapman and Hall, London.
HOLLANDER, M. and WOLFE, D.A. (1973). Nonparametric Statistical Methods, pp. 219–228; 68–74. Wiley-Interscience, New York.
MICHALOPOULOS, G., SATTLER, G.L., O'CONNOR, L. and PITOT, H.C. (1978). Unscheduled DNA synthesis induced by procarcinogens in suspensions and primary cultures of hepatocytes on collagen membranes. Cancer Res. 38:1966–1971.
MILLER, R.G., Jr. (1981). Simultaneous Statistical Inference, pp. 76–81, 2nd Ed. Springer-Verlag, Heidelberg.
MITCHELL, A.D., CASCIANO, D.A., MELTZ, M.L., ROBINSON, D.E., SAN, R.H.C., WILLIAMS, G.M. and VON HALLE, E.S. (1983). Unscheduled DNA synthesis tests: A report of the U.S. Environmental Protection Agency Gene-Tox Program. Mutation Res. 123:363–410.
NATER, J. and WASSERMAN, W. (1974). Applied Linear Statistical Models, pp. 480–482. Irwin, Homewood, Illinois.
PROBST, G.S., McMAHON, R.E., HILL, E.E., THOMPSON, C.Z., EPP, J.K. and NEAL,S.B. (1981). Chemically-induced unscheduled DNA synthesis in primary rat hepatocyte cultures: A comparison with bacterial mutagenicity using 218 compounds. Environ. Mutagen. 3:11–32.
SAS (1983). SAS Institute Inc., Raleigh, North Carolina.
THAKUR, A.K. (1984). A FORTRAN program to perform the nonparametric TerpstraJonckheere test. Comput. Progr. Biomed. 18:235–240.
THAKUR, A. K. (1985). Tests of homogeneity and trend with medians. Environ. Mutagen. 7 (suppl. 4):23–30.
THAKUR, A.K., BERRY, K.J. and MIELKE, P.W., Jr. (1985). A FORTRAN program for testing trend and homogeneity in proportions. Comput. Progr. Biomed. 19:229–233.
WESLEY, R. and WESLEY, M. (1982). A program to compute power of Fisher test at interim point in a clinical trial. Comput. Progr. Biomed. 14:67–72.
WILLIAMS, G.M. (1976). Carcinogen-induced repair in primary rat liver cell cultures; a possible screen for chemical carcinogens. Cancer Lett. 1:231–236.
WILLIAMS, G.M. (1977). Detection of chemical carcinogens by unscheduled DNA synthesis in rat liver primary cell cultures. Cancer Res. 37:1845–1851.
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Thakur, A.K. Unscheduled DNA synthesis: Some statistical thoughts. Cell Biol Toxicol 3, 175–192 (1987). https://doi.org/10.1007/BF00058455
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DOI: https://doi.org/10.1007/BF00058455