FIELD D 

 Columns 12, 13, 14, 

 15, 16, and 17 



the action, coded in Field T-2, produced by the secondary compound; i. e. , it does not signify a 

 special use for Field D as does an asterisk in Column 17 (see Division 4). 



6. Data from tests using secondary compounds of uncertain identity are coded only exceptionally 



Test data involving secondary compounds that are ill- defined have not ordinarily been selected 

 for inclusion in the CBCC files, just as data involving test compounds of uncertain identity have 

 seldom been selected. For example, data involving materials such as natural or synthetic mixtures, 

 extracts, vaccines, etc. have seldom been coded. Occasionally, exceptions have been made and 

 such data are coded, necessitating classifying and assigning a CBCC designation to the material 

 coded as a secondary compound. Materials known to be discrete chemicals have more frequently been 

 given CBCC Serial Numbers than have extracts, vaccines, natural product mixtures, etc. , even though 

 the lack of knowledge of their structures makes their processing irregular. In Field D, coding of 

 materials of uncertain identity must be, for each case, the result of special deliberation and a decision, 

 in order to bestow on that material recognition as a distinct chemistry file entry with a unique reference 

 number. 



7. Enzymes are NOT CODED IN FIELD D as secondary compounds when their BIOLOGICAL 

 ACTIONS are affected by test compounds; however, if their metabolic fate is affected by 

 the test compound, as indicated in Field T-2, they can be coded as secondary compounds 

 in Field D 



The coding of a test compound's effect on the activity of an enzyme deviates slightly from the 

 usual procedure of coding in Field D the compound whose activity is affected by the test compound. 

 It will be noted that the Code provides for enzymes being coded in Field T-2, symbol series 7 — ; 

 therefore, the purpose that would be served by placing this "secondary" compound, the enzyme, in 

 Field D is satisfied by the entry in Field T-2 and placing it in Field D as well as in Field T-2 would 

 be not only unnecessary but confusing to the interpretation of the code line. 



Therefore, when a test compound (1) has an effect on the action of an enzyme (e. g. , inhibits 

 or enhances an enzyme's action ) or (2) has an effect on the action of a secondary compound which in 

 turn affects an enzyme action (e. g. , antagonizes, synergizes, or simulates the secondary compound's 

 action on an enzyme action ) or (3) is a coenzyme for an enzyme action , the enzyme is always coded in 

 Field T-2 and never in Field D, even though it is in a sense a secondary compound. 



In contrast to this, when there is not being coded the test compound's effect on an enzyme 

 action , but the test compound's effect on an enzyme's synthesis, destruction, excretion, etc. (Field 

 T-2, Symbols F8--, FE--, FF--, etc. ), the enzyme is written and its CBCC serial number (not its 

 Field T-2 symbol) is coded in Field D. 



The SUBSTRATE of an enzyme affected by a test compound is never to be considered as a 

 secondary compound and is never coded in Field D. 



8. A carcinogen that produced a tumor being treated is not a secondary compound 



In the case of coding the action of a test compound (which is not being tested as a carcinogen) 

 on a tumor which was induced by a carcinogen, the carcinogen is not to be considered as a secondary 

 compound and is therefore not to be coded in Field D. The description, origin, or source of the tumor 

 is coded by Symbols S through Z in Field F. 



9. The action of the secondary compound can not be coded 



When Field D is used to code a compound whose action is synergized, antagonized, or 

 simulated by the test compound or is additive with the action of the test compound (see the first of 

 the four uses itemized under the section on General Use), this is indicated by the Symbols 8, 9, A, 

 or C of Field T-l. Note that it is the secondary compound's action that is affected by the test 

 compound and it is the biological state, quality, or process on which the secondary compound acts 

 that is coded in Field T-2. It is impossible to code the action of the secondary compound (Symbols I, 

 2, 3, e. g. ), because Field T- 1 must be used for the test compound's effect on the action (Symbols 8, 

 9, A, or C). Ideally, there should be a second Field T- 1 for coding the action of a secondary 



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