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Study Information
Study Attribute Value
CEBS Accession Number: 002-01073-0002-0000-5
Chemical Name: 1,3-Dichloro-5,5-dimethylhydantoin
CASRN: 118-52-5
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 807055_CA
Study Result: Negative

Study Result: Negative
Activation Trial Trial Call
No Activation  Negative 
Induced Rat Liver S9  1_S9  Negative 
Induced Rat Liver S9  2_S9  Negative 

Trial #:1   Activation: No Activation    Date: 02/24/1982    Harvest Time: 14 hour(s)   Trial Call: Negative   
  Dose
µg/mL
Total
Cells Examined
Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
Vehicle Control: Dimethyl Sulfoxide
0         
100 4 0.040 4.0 1 0.010 1.0 3 0.030 3.0 0 0.000 0.0
Test Chemical: 1,3-Dichloro-5,5-dimethylhydantoin
 0.5       
100 4 0.040 4.0 0 0.000 0.0 4 0.040 4.0 0 0.000 0.0
1.6       
100 6 0.060 4.0 1 0.010 1.0 5 0.050 4.0 0 0.000 0.0
5         
100 4 0.040 4.0 0 0.000 0.0 4 0.040 4.0 0 0.000 0.0
16         
100 14 0.140 8.0 7 0.070 5.0 6 0.060 4.0 1 0.010 1.0
Positive Control: Mitomycin-C
 0.15      
100 38 0.380 25.0 10 0.100 10.0 28 0.280 20.0 0 0.000 0.0
Trend: 1.184 2.157 0.331  
Probability: 0.118 0.016 0.370  


Trial #:1_S9   Activation: Induced Rat Liver S9    Date: 06/10/1982    Harvest Time: 14 hour(s)   Trial Call: Negative   
  Dose
µg/mL
Total
Cells Examined
Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
Vehicle Control: Dimethyl Sulfoxide
0         
100 2 0.020 2.0 1 0.010 1.0 1 0.010 1.0 0 0.000 0.0
Test Chemical: 1,3-Dichloro-5,5-dimethylhydantoin
8         
100 7 0.070 7.0 1 0.010 1.0 6 0.060 6.0 0 0.000 0.0
12         
100 10 0.100 7.0 2 0.020 2.0 8 0.080 6.0 0 0.000 0.0
16         
100 7 0.070 7.0 2 0.020 2.0 5 0.050 5.0 0 0.000 0.0
Positive Control: Cyclophosphamide
15         
100 25 0.250 22.0 9 0.090 9.0 16 0.160 14.0 0 0.000 0.0
Trend: 1.454 0.753 1.324  
Probability: 0.073 0.226 0.093  


Trial #:2_S9   Activation: Induced Rat Liver S9    Date: 02/24/1982    Harvest Time: 14 hour(s)   Trial Call: Negative   
  Dose
µg/mL
Total
Cells Examined
Total Aberrations Complex Aberrations Simple Aberrations Other Abs
No. of
Abs
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
No. of
Abs.
Abs
Per
Cell
% Cells
With
Abs
Vehicle Control: Dimethyl Sulfoxide
0         
100 10 0.100 10.0 2 0.020 2.0 8 0.080 8.0 0 0.000 0.0
Test Chemical: 1,3-Dichloro-5,5-dimethylhydantoin
1.6       
100 5 0.050 5.0 0 0.000 0.0 5 0.050 5.0 0 0.000 0.0
5         
100 7 0.070 6.0 2 0.020 1.0 5 0.050 5.0 0 0.000 0.0
16         
100 12 0.120 10.0 4 0.040 4.0 8 0.080 7.0 0 0.000 0.0
Positive Control: Cyclophosphamide
15         
100 12 0.120 12.0 3 0.030 3.0 9 0.090 9.0 0 0.000 0.0
Trend: 0.087 1.198 -0.275  
Probability: 0.465 0.116 0.608