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Study Information
Study Attribute Value
CEBS Accession Number: 002-01148-0001-0000-7
Chemical Name: 2',3'-Dideoxycytidine
CASRN: 7481-89-2
NTP Study Type: Genetic Toxicology - Mammalian Cell Cytogenetics
NTP Study ID: 955544_SCE
Study Result: Positive

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

Trial #: 1    Activation: No Activation    Date: 01/09/1990    Trial Call: Positive   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Water 
0         
 50 1041 360 0.346 7.20 26.0 0.000
Test Chemical 2',3'-Dideoxycytidine 
16         
 50 1047 391 0.373 7.82 26.0 7.989 
49         
 50 1046 447 0.427 8.94 26.0 23.573 
163         
 50 1047 649 0.620 12.98 26.0 79.245 
490         
 0 0 0 0.000 0.00 0.0 N/A
Positive Control Mitomycin-C 
 0.001     
 50 1046 588 0.562 11.76 26.0 62.553
Mitomycin-C 
 0.004     
 10 211 180 0.853 18.00 26.0 146.682
Trend: 9.589        
Probability: 0.000        

Trial #: 2    Activation: No Activation    Date: 02/06/1990    Trial Call: Positive   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Water 
0         
 50 1050 399 0.380 7.98 31.0 0.000
Water 
0         
 50 1049 360 0.343 7.20 26.0 -9.688
Test Chemical 2',3'-Dideoxycytidine 
50         
 50 1048 515 0.491 10.30 26.0 29.319 
167         
 50 1045 603 0.577 12.06 26.0 51.851 
500         
 50 1046 1077 1.030 21.54 31.0 170.957
Positive Control Mitomycin-C 
 0.001     
 50 1048 555 0.530 11.10 26.0 39.363
Mitomycin-C 
 0.004     
 10 208 182 0.875 18.20 26.0 130.263
Trend: 18.581        
Probability: 0.000        

Trial #: 1_S9    Activation: Induced Rat Liver S9    Date: 01/09/1990    Trial Call: Positive   
  Dose
µg/mL		 Number
Cells
Examined		 Number
Chromosomes
Examined		 Total
Number
SCEs		 SCE /
Chromosome		 SCE /
Cell		 Hours in
BRDU		 % Increase
Over Solvent
Control
Vehicle Control Water 
0         
 50 1047 354 0.338 7.08 26.0 0.000
Test Chemical 2',3'-Dideoxycytidine 
490         
 50 1045 478 0.457 9.56 26.0 35.287 
1633         
 50 1047 500 0.478 10.00 26.0 41.243 
4900         
 50 1047 618 0.590 12.36 26.0 74.576
Positive Control Cyclophosphamide 
 0.125     
 50 1048 544 0.519 10.88 26.0 53.526
Cyclophosphamide 
 0.5       
 10 210 190 0.905 19.00 26.0 167.595
Trend: 8.205        
Probability: 0.000