FIELDS G-I and G-2 

 Columns 27 and 28 



10. Pretreatments represented by Symbols 2, P, Q, and R; distinctions of definitions and use 

 of the four symbols 



Symbols 2, P, Q, and R represent experimental states that are often particularly significant and 

 their use deserves some explanatory discussion. These conditions are the result of deliberate chemical 

 or surgical pretreatments which are preparatory for the experiment with the test compound. Such pre- 

 treatments might all have been assigned a single code symbol with the general definition "chemical or 

 surgical pretreatment of the organism or organ". However, since there is advantage in being more 

 specific, the pretreatments have been further classified into four types. For clarity in distinction, 

 Symbols P, Q, and R are described prior to Symbol 2. 



NOTE THAT SYMBOLS 2, P, Q, and R, as well as all other symbols of Field G (with the exception 

 of Symbol Z), DESCRIBE ONLY PRE TREATMENTS, according to the symbols' definitions, AND NEVER 

 DESCRIBE A TREATMENT COMPARABLE TO THE TREATMENT WITH THE TEST COMPOUND. If, for example, 

 the removal of an organ or a tissue is in part responsible for the action coded in Field T-2 (i. e. , if the 

 response coded in Field T-2 is due to surgical treatment as well as treatment with the test compound), 

 the surgical treatment can not be indicated by Symbols 2, P, Q, or R, nor can it be coded specifically 

 by any symbol. Only by Symbol Z can the fact be coded that the test compound is not entirely respon- 

 sible for the action and that another, non- chemical treatment was in part responsible. 



A. Symbols P, Q, and R 



The objective of the pretreatments included here is the isolation of the organism or organ 

 from one or more physiological factors that normally influence it. Examples of such pre- 

 treatments illustrate the distinction in uses of the three symbols, as follows: 



Symbol P (test compound action on the organism or organism part OTHER THAN the organ 

 isolated ): 



(1) Isolation of the organism from the influence of one or more of its specific parts by 

 extirpation of that part, such as removal of the spleen. The excised organ is not 

 coded in Field H-l, because it is not an organ responding to treatment with the test 

 compound, but is a discarded organ; what remains of the organism is treated with the 

 test compound. (The excised organ is coded, however, in Field H-2. ) 



(2) Isolation of the organism from the activity of a specific organ left in situ . This is 

 possible by selectively cutting or drugging the nerve supply of that organ, e. g. 

 The organ rendered functionless is coded in Field H-2 (never in Field H-l). If the 



in situ preparation is accomplished by blocking or destroying nerves or blood vessels 

 of the organ, the nerves or blood vessels can not be coded, but the procedure should 

 be in the written abstract of Field G. On the other hand, if the organ rendered func- 

 tionless is a specific nerve or group of nerves or a blood vessel, instead of an organ 

 served by the nerve or vessel, it is coded in Field H-2 and it is understood that all 

 effects of that nerve or blood vessel on all organs supplied by it are thereby 

 abolished. 



The removal of a gland to produce a specific incidental hormonal deficiency (i. e. , a 

 hormone deficiency not specifically treated by the test compound) would be coded by 

 Symbol P except that a special symbol for this particular condition is provided 

 (Symbol B) and should always be used rather than Symbol P. 



Symbol Q (test compound action on the in situ organ isolated): 



In situ isolation of the organ coded in Field H- 1. This includes the isolation of an organ 

 from material it ordinarily processes, such as the short-circuiting of food around an isolated 

 experimental part of the alimentary tract (Pavlov pouch, intestinal loop, etc. ). It also in- 

 cludes isolation of an organ from the body as a whole, such as severing or freezinq the 

 nerve supplying the organ or blood circulating to the organ (the nerve or blood vessel of 

 which preparation would not be coded in Field H-2). 



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