FIELD D 

 Columns 12, 13, 14, 

 15, 16, and 17 



A compound to which cross tolerance or cross tachyphylaxis, is produced 

 by administration of the test compound. (See Symbols 514 and 5131 in 

 Field T-2. ) 



Specific Directions and Explanations 



1. Use of Field D is determined and directed by other fields of the Code 



As explained above, under "General Use", Field D is coded only when the definition of a 

 symbol in another field of the Code specifically directs the coder to do so; these specific uses of 

 Field D are described in subsequent divisions. 



2. Field D can never have more than one compound coded in any one line 



Double coding (i. e. , coding two compounds) in Field D is never permitted, because it is 

 impossible to designate, in any way that will distinguish them, more than a single compound in a 

 given field on an IBM punched card. Therefore, in a situation where two (or more) secondary 

 compounds, each administered with the test compound in independent tests, are found to have their 

 actions affected by the test compound to so nearly the same degree that the coding of the data would 

 be identical for both of the compounds (except for coding in Field D), Field D can not be double coded 

 with all of the secondary compounds to condense the data into a single line. A separate line must be 

 coded for each secondary compound, even though the code lines are identical except for Field D. 



3. Two or more secondary compounds, all essential and all administered together; Symbol ff in 

 Column 16 



Occasionally, data are encountered in which the test compound is tested for an effect on the 

 action of two or more essential secondary compounds administered together , (i. e. , the action of the 

 secondary compounds would not occur if one of them were absent) rather than on the action of a single 

 secondary compound. (Note that this does not refer to mere mixtures of secondary compounds, any 

 one compound of which may produce the action; mixtures are seldom, if ever, coded in Field D by the 

 CBCC. ) In this situation, the two or more secondary compounds are all essential components of a 

 single test (in contrast to the situation described in Division 2 above, where the two or more secondary 

 compounds bear relationship to the action of the test compound through independent tests). Since 

 Field D can be coded with but a single chemical and since it is important that there be coded all of 

 those secondary compounds that produce together the action affected by the test compound, A CODE 

 LINE IS PREPARED FOR EACH MEMBER OF THE SECONDARY COMPOUND COMBINATION, all the lines 

 being identical except for Field D. As a means of relating these lines and indicating by code the 

 situation just described, SYMBOL # IS PLACED IN COLUMN 16 of each of these related lines; Symbol # 

 is used in Column 16 ONLY in coding this situation. Place this symbol at the top of the code box so 

 that room is left in the box for the entry of the fifth unit of the compound's symbol. 



4. Standard of comparison coded as a secondary compound; Symbol * in Column 17 



To designate that a compound is used as a standard for comparison in evaluating the test 

 compound action, place Symbol * in Column 17. Place this asterisk at the top of the code box so that 

 room is left for the entry of the sixth unit of the compound's symbol in the box. The presence of an 

 asterisk in this column indicates that the secondary compound is known to produce the action coded 

 in Field T-2 when tested alone and the degree of action of the test compound is evaluated by compar- 

 ison to the known degree of action of the secondary compound; it distinguishes this use of Field D 

 from the other uses of the field. 



5. Radioactivity of the secondary compound; Symbol * in Column 16 



To designate that the secondary compound is radioactive , enter Symbol * in Column 16. Place 

 this symbol at the top of the code box so that room is left for the entry of the fifth unit of the compound's 

 symbol in the box. Note that the asterisk in Column 16 merely gives added information about a special 

 property of the secondary compound. It does not affect the interpretation that the test compound alters 



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