Table II.

Results of R-Based Statistical Analyses (Lutz and Lutz model)

Chemical (trial no.)	td	Confidence Interval for td	b	Confidence Interval for b	p Value
Beads (1)	−0.939	0.0, 0.160	0.107	0.105, 0.108	1
Beads (2)	−0.857	0.0, 0.467	0.0745	0.073, 0.076	0.99
Colchicine (1)	2.732	2.689, 2.773	5.863	5.671, 6.056	0
Colchicine (2)	2.811	2.690, 2.921	0.998	0.945, 1.052	0
Vinblastine (1)	0.178	0.165, 0.210	5.751	5.209, 7.132	0
Vinblastine (2)	0.208	0.166, 0.229	4.433	3.688, 4.935	8.88e-16
ENU (1)	2.34	1.319, 2.917	0.074	0.066, 0.081	0.003
ENU (2)	5.845	2.933, 8.322	0.051	0.036, 0.069	0.0002
MNU (1)	0.357	0.231, 0.500	0.831	0.746, 0.924	0.0003
MNU (2)	0.259	0.191, 0.356	2.87	2.549, 3.303	1.44e-05
EMS (1)	8.074	7.372, 8.710	0.316	0.296, 0.336	0
EMS (2)	7.581	4.762, 9.139	0.058	0.046, 0.067	9.33e-06
MMS (1)	0.804	0.266, 1.280	0.561	0.462, 0.673	0.022
MMS (2)	0.723	0.404, 0.877	1.287	1.013, 1.482	3.22e-05
Bleomycin (1)	−0.066	0.0, 0.001	31.501	28.98, 34.03	1
Bleomycin (2)	−1.370	0.0, 0.002	5.948	5.33, 6.56	1

td = Best estimate of the threshold dose

b = Best estimate for the slope above the threshold dose

p Value < 0.05 with confidence intervals that do not include zero indicates statistically better fit for threshold model.

p Value ≥ 0.05 indicates linear fit cannot be rejected.