FIELD Q 

 Column 52 



SEE OF INOCULUM OR IMPLANT 



Organization 



In Field Q, symbols are assigned to nine ranges of numbers, the range increment (xlO) being 

 considered representative of typical inoculations and adequate for ordinary distinctions between tests 

 differing in respect to inoculum size. The repetition of the list of symbols, expressing the definitions 

 in a different way, is merely for convenience, since authors may express inoculum size in either 

 terminology. 



General Use 



Field Q is used to record the number of individuals of the unicellular organism coded in Field E 

 (e. g. , Protozoa or Bacteria) or the number of cells of the cancer coded in Field E, contained in the inoc- 

 ulum or implant made to the host coded in Field J. The field is used also to record the number of indi- 

 viduals of any infective stage of a parasitic test organism coded in Field E, introduced into the host 

 coded in Field J. 



Specific Directions and Explanations 



1. Coding in Field Q when the inoculum size is expressed as being within a range 



Occasionally an inoculation is made in which the size is expressed only as being somewhere 

 between an upper and lower limit; for example, an inoculum of "from 10 3 to 10 5 cells". Field Q must 

 never be coded with two symbols representing the possible minimum and maximum size of such an 

 inoculum, because such coding would imply that two separate tests had been run, one with a small 

 inoculum, the other with a large inoculum (as explained in Division 6). Instead, Field Q would be 

 coded with an average. (In the example given, 50,500 cells would be coded, using Symbol 5. ) 



2. Definition of the entry in Field Q 



The definitions for symbols of Field Q are exclusively in terms of the total number of cells or 

 individuals of each inoculum or implant; therefore, a Field Q entry is never in terms of the number of 

 cells or individuals per unit of volume or weight of the suspending medium. If data are given in terms 

 of numbers per unit volume or weight of implant or inoculum and the total number of cells or individuals 

 inoculated or implanted can not be calculated, no entry is to be made in this field. 



Development of a population of implanted organisms, subsequent to the implantation depends 

 on the test organism species involved. Certain organisms, notably many helminths, can not complete 

 their life cycles within the host into which they are inoculated and consequently the population resulting 

 from the inoculation and the degree of severity of the associated pathology is limited to the number of 

 individuals introduced. Other organisms (Bacteria and Protozoa) can reproduce indefinitely within the 

 host and the final population and severity of an associated pathology is limited only by natural tissue 

 barriers or immune factors in the host or by death of the host. The size of the population of test organ- 

 isms, such as most Bacteria or Protozoa, at the time of treatment, or the size that would be expected at 

 the time of evaluation , if there had been no treatment, is dependent on the two factors, size of the 

 inoculum and length of time from inoculation. The CBCC has not required the coder to be able to distin- 

 guish the two situations, thus no code symbol is provided for indicating that the inoculum size is the 

 same as the final population size, as opposed to its being less than the final size. Thus, there is no 

 indication in Field Q as to whether the inoculum size is finite (just as when six test organism individuals, 

 not in a host, are used in a single test) or whether it represents only a beginning population which can 

 reproduce to an indefinite size. The interpreter of the code line, however, must be able to interpret 

 the coding of Field Q with respect to a knowledge of the test organism's capacity for reproduction in 

 the host (i. e. , its life cycle) and with respect to the number of organisms normally expected after a 

 given period of time. 



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