FIELDS M and N 

 Columns 45 and 46; 

 47 and 48 



7. Dosag e to be coded when the test compound is added to and distributed through a host 

 MEDIUM and the final concentration is determined 



When a test compound is added to a host environment (i. e. , the environment of a test organism) 

 coded in Field J (e. g. , a nutrient medium, a natural environment such as water or air, the fluid of a 

 tissue or cell suspension, etc. ), the dosage to be coded in Fields M and N is preferably the concen- 

 tration after complete dispersion in this host, whenever this is known or can be calculated. (This is 

 also discussed in Division 6 above as Situation [2], ) When this final concentration is coded in 

 Fields M and N as the dosage, the administration of that recorded concentration can no longer be 

 regarded as being to the host environment coded in Field J but must be regarded as being to the test 

 organism in Field E. Therefore, it is appropriate that all coding in Fields A, B, and C must describe 

 the state after distribution through the test organism's environmental medium; the state and any solvents 

 of the test compound prior to introduction to the host environment will not be coded. By coding the 

 Symbol § in Fields M and/or N (whichever is used), the fact is indicated that the host coded in Field J 

 is actually the diluent and that the coded dose is the dose applied to the test organism or tumor coded 

 in Field E. 



If a test compound is applied to such a host environment or culture medium and only the quantity 

 or concentration initially given to the medium is known (i. e. , the final concentration in the medium is 

 unknown), the dose coded in Fields M and N will be that given to the medium, Fields M and N will not 

 be coded with Symbol # and coding in Fields A, B, and C will describe the state when added to the 

 medium. For example, if the concentration is given in terms of a gas which is subsequently streamed 

 through, or otherwise exposed to, (1) a bath or perfusate of a tissue macerate or (2) an enzyme-containing 

 secretion (e. g. , milk), the concentration of the applied gas may be coded in Field M, regardless of the 

 unknown factor of its solubility. In this case, Field A must be coded with "gas", Symbol 1, and Fields 

 B and C would not be coded, since the test compound was not in a solvent or conditioning agent when 

 it was added to the host liquid. If, however, the author should actually have determined the dissolved 

 concentration of the test compound, coding in Fields M and N should be based on that concentration 

 with the Symbol # in Columns 46 and/or 48, Field A coded with "solution", and Field C is coded with 

 the bath (water, saline, etc. ). 



8. Relationship between the dosage fields (Fields M and N) and Fields E, H, and I when Field J 

 is coded; use of Symbol (IBM zone punch) when Field J is coded 



A further provision is stipulated for a testing situation that is doubtless infrequent. It is 

 described with the belief that by presenting and discussing all possible situations and all relations 

 with other fields, the pattern of coding Fields M and N will be better comprehended. If an author has 

 determined by some analytical procedure the actual amount of test compound at the site of action when 

 the action is on an organ, tissue or cell structure of the test organism in Field E and this test organism 

 is maintained in a host coded in Field J (living or non-living), that dosage should be the one coded in 

 Fields M and N, rather than the amount given to the gross host or the gross test organism. In this 

 case, the IBM zone punch is coded in Fields M and/or N, Columns 46 and/or 48, to designate that 

 it is not the dose applied to the host in Field J nor the dose applied to the gross test organism in 

 Field E, but it is the dose present at the organ or tissue site of action in the test organism . This organ 

 or tissue may or may not be the organ or tissue coded in Fields H and I, as explained in the following 

 two paragraphs. 



It will be recalled that if a culture medium or environment (i. e. , a non-living host) is coded 

 in Field J, it is so indicated by the IBM zone punch in Column 37 of Field J (i. e. , by the use of 

 code symbols beginning with any of letters S through Z in Field J) and this is in turn an indication 

 that any accompanying coding in Fields H and I represents organs or tissues or cell parts of the test 

 organism in Field E rather than of the entry in Field J. Therefore, when Fields M and N are coded with 

 the zone punch in Columns 46 or 48, and Field J is coded with symbols beginning with any of letters 

 S-Z in Column 37 (i. e. , is also coded with zone punch 0), the organ, tissue, or cell part to which the 

 coded dose is applied will be the structure coded in Fields H and I. 



However, when Fields M and N are coded with the zone punch in Columns 46 and 48, and 

 Field J is coded with symbols beginning with anything other than S-Z, the organ, tissue, or cell part 



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