FIELDS W, X, and Y 



Columns 68; 69 and 



70; and 71 



Unfortunately, an author frequently expresses his positive test results only in terms of a 

 comparative evaluation so that the CBCC coder has available no measure of intensity of response or 

 "potency" that can be used for coding. In this case, there is no recourse but to record the author's 

 expression as well as possible and the person using the CBCC file has consequently always to 

 interpret this author's expression in the light of whatever the author used as a factor for comparison. 



Of these authors' evaluations, the least satisfactory for the CBCC is the author's use of mere 

 verbal expressions (e. g. , "ineffective", "low", "inactive", "high") or a simple scoring system; 

 frequently, the author, in arriving at his verbal or scoring evaluation, has done so by relating it to 

 the special character of the biological field involved and by comparing it to known actions under other 

 conditions (known actions of other compounds, e. g. ), but this is not necessarily always the case; it 

 is an interpretation the CBCC would prefer delegating to the user of its files by supplying in Field Y 

 only the measure of the response. Nevertheless, when nothing but an author's interpretation is avail- 

 able- -his verbal expression or his scoring evaluation, the only coding possible is by Criterion 01 

 or 02 and the person subsequently using the CBCC files must make what interpretation he can of the 

 coding of this author's evaluation by studying the written abstract (as well as the coding) of the biology 

 code line. 



An author's comparative expression of test results is frequently by comparison to a standard 

 compound. Thus, the coder may be supplied with nothing but this comparative expression (e. g. , "50% 

 of the response of compound X" or "the test compound had to be administered in twice the amount of 

 Compound X to produce the peak action of Compound X"); in other words, the author may not reveal 

 what was the measure of response of the test compound which, when compared to this standard 

 compound, gave the comparative evaluations ("50%" or "twice as much"). In this case also, the 

 coder has no choice but to code the comparative expression supplied by the author and the user of the 

 CBCC files must interpret the expression as best he can by studying the CBCC biology code line and 

 by learning what he can of the response to the standard compound. Criteria 03 and 04 have been 

 included in Field X, with a fixed scale for coding Field Y, for those comparative expressions of 

 evaluation. They are described thoroughly in Division 9. 



8. Rating of the biological activity of chemicals on the basis of the QUANTITY of the chemical 

 needed for a GIVEN INTENSITY of biological response (POTENCY) 



In these descriptions of evaluation criteria, the term "potency" is used to describe a test 

 compound's capacity for causing a biological response. Thus, a compound which did not cause a 

 particular response regardless of the quantity administered would be described as having zero potency 

 for causing that response; the data would be negative. When the test compound does produce the 

 response, however, its potency is measured by two factors: intensity of response and minimum dose 

 needed to produce that intensity of response. The smaller the quantity needed to produce a given 

 intensity of response, or the greater the response intensity to a given quantity, the higher is the 

 compound's potency. The following sections, A and B, discuss and define "intensity of response", 

 the consideration of which is important before the concept of "potency" is further discussed. 



A. Intensity of response in a SINGLE INDIVIDUAL ORGANISM 



Intensity of response is most easily understood as a variable in a single individual 

 organism, varying with the dose size administered, up to a point of maximum degree to 

 which the test compound is capable of inducing the response or to the maximum degree to 

 which the organism is capable of making the response. 



Not all specific responses of Field T, as they occur in the individual organism, lend 

 themselves to precise measurement in terms of "intensity". In particular, attention is 

 called to the responses whose definitions exclude any intensity variation in the individual 

 organism: death (toxicity, Symbols 11, 111, and 112 of Field T-2) or cure (Symbol 172), 

 for example. Also, when no definite terminal or maximal intensity can be fixed for a 

 response which does vary in intensity, expression of degree of intensity is difficult or 

 impossible; many Field T-2 responses, when caused by the test compound rather than 

 altered by the test compound, exemplify this: the locally toxic responses (symbol series 

 1 13-) when caused by the test compound, or production of edema, thrombosis, fibrosis, 

 neoplasms, pain, hyperpnea, etc. The intensity of these can not be expressed as a per 



183 



