FIELD T- 1 

 Column 57 



the data include description of the action as well as the stipulation that the action simulates that of 

 a second compound (instead of indicating only the fact that the test compound simulated the second), 

 a line should be constructed to code this action of the test compound on the same Code Sheet. 



15. Symbols D, E, F, and G; coding of the test compound's influence (Field T-l) on the action 

 (not coded) of a nerve (Field H) on a physiological process (Field T-2) 



In the same way that a test compound may alter the action of a secondary compound (see 

 Division 12, Symbols 8 and 9), a test compound can influence the action that a specific nerve has on 

 a given biological part or process. Examples of such processes controlled or affected by nerves are 

 heart rate (Field T-2, Symbol CI), vascular dilation (Symbol 8215), gland secretion (Symbol FC), 

 skeletal muscle contraction (Symbol 813), etc. When a test compound intercedes in this nervous 

 control or nerve effect, it should be coded specifically as such. The situation exists particularly in 

 the case of those tests using anatomical preparations (frequently in vitro ) which consist of an effector 

 end organ (heart, skeletal muscle, gland, etc. ) and its controlling anatomical nerve. The normal 

 nervous effect on the end organ is demonstrated and measured by artificial stimulation of the nerve; 

 subsequently, the test compound is administered, its effect being interpreted as the alteration of the 

 degree of the end organ's response to the nerve, when the nerve is given a stimulus equal to that 

 stimulus administered prior to administration of the chemical. For such special data, four symbols 

 are provided, D, E, F, and G. 



Symbols D and E are used to indicate that the test compound acts to inhibit the nerve's normal 

 action; Symbols F and G are used to indicate that the test compound acts to intensify the nerve's 

 normal action. It will be recalled that, in the case of coding a test compound's effects on a secondary 

 compound's action (e. g. , Symbols 8 and 9 of Field T-l), the secondary compound's action can not be 

 coded; similarly, when coding a test compound's effect on the action of a nerve, there is no special 

 coding field in which to code the nerve's normal action. This disadvantage, however, is largely 

 compensated for by having two symbols for each of inhibitory and intensifying chemical action, one 

 symbol (D or F) indicating that the nerve normally increased or caused the biological process coded in 

 Field T-2, the other symbol (E or G) indicating that the nerve normally inhibited or prevented the 

 biological process. 



Use of these symbols and coding of chemical effects on nerve actions on end organs is dis- 

 cussed in Division 8 of Specific Directions and Explanations for Fields H-l and H-2. 



16. Symbols J, K, L, M, N, and 0; coding of the test compound's ameliorative or curative action 

 on a pathological state or process, coded in Field T-2 as a symptom of a disea se coded 



in Field E; return of the test organism to a normal state 



The coding of pathology is dealt with extensively in the Key section on the Pathology Code of 

 Field E, as well as in certain previous divisions of these specific directions and explanations for 

 Field T-l (Divisions 7, 8, and 11). In the section of the Pathology Code, it is explained that the 

 CBCC takes advantage of Field T-2 to code specific symptoms of general pathological states coded in 

 Field E, when the response of those specific symptoms represents the test compound's effect rather 

 than the response of the entire symptomatology of the disease. 



As has been pointed out in previous divisions (especially Divisions 7, 8, and 11), the items 

 of Field T-2 are of three categories. Of these, the two major types (distinguished in Divisions 7 and 

 8) are: 



(1) Those representing normal states or processes that can be affected by test 

 compounds or by pathologies coded in Field E. 



(2) Those that represent pathological states or processes that can be caused by 

 the test compound or treated by the test compound. 



The third category (described in Division 11) consists of Field T-2 terms representing stages 

 of cure or partial recovery from a disease coded in Field E (Field T-2 items of the 17-- series) or 

 stages of exacerbation of a disease coded in Field E (Field T-2 items of the 16-- series), all of which 

 are coded only with Symbol 7 of Field T-l. 



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