I^^^.VVjs — .J^'has'been Studied Intenslvelyand there Is a body of expert opinion "*'--'*?r'5'.>i§: 



■ V?-. '.•^"x.:'' ■■-" which considers' that It Is possible that It may correlate closely jj;^- ^•'^';*^'^' 



"*,'. "' "^•'".%^'^_^;*;'wlth Idhger-lerm'carclnogenlc effects. The majority of the other •■ "'. i!'-*/^ 



JT ,.- :*t" • - ■;^"^ inariy blologYcal reactions that have been studied seem more "^ " • ^''\ '-^ 



-. '■.■>*---• -^ related to Immediate toxic effects than anything else. The '">=■• '^''''.'■^ 



'_^.',_: ,,_;':.■•' Conference took note with interest of B. A. T. (Hamburg) experiments '•./,•. "I' 



• . . .,_.-'-■. ■^'. and also of T.R.C.'s collaboration with Professor Latner on studying ^- .; 'T: 



i- * feefi-- -i-dX" the relative amount of. Lactic Acid Dehydrogenase Isoenzymes.^ ■-!_ , .«^ 



■; : -^v ■■■= •»''C*-''«.^-'^-s -^»>■-'--i•'>^ * "^ • -■ ■-■■'.\-- - : ■' -v'- ■ - ■' r 



. . ■ In an attempt to take a broad view of this complicated situation, 

 :.'.■ ■.•',■• the Conference reached the following conclusions: . . '. . ^^ •. '-'.'■< 



(a) ■ ' In the foreseeable future, say five years, mouse-skin 



painting would remain as the ultimate court of appeal on ' ' 

 carcinogenic effects.""; - .' " ' '' t' '.'- • ' 



401 





There was a possibility that short-term cellular phenomena - ' 

 such as hyperplasia, sebaceous gland suppression, alteration ■. i •._. 



'-.t^,^ in cell metabolism, reaction of chicken embryo membrane, "r-"'. '••';*: 



"might develop sufficient credibility to lighten the burden of .i'- -f. 



■;*' ' '^xf^T'.l'* mouse-skin work by screening.' ^'•>.'-:-»-*-"/^-;' -;■••--- '. \' ■^ 



*■. 'i!-'*^.W'?-iJ^i <,!;■> '*K ■-' - ■ ! - ' - -• •-■'.-■ "^.'t:^- .-."■^; ' : l•^ .' '" ' .'•.■ t. 



■•-'. "V' ''.(c) '-'However the pr'eceedlng decision developed. It was '.'~: .' . '{■ 

 ■■«;'?;, •''^.' already clear that techniques such as hyperplasia, . ■,'• 

 "^ .-|.j. ■ /•• observation of goblet cell activity, and anything that 

 ■. **.i'.' -•' could be directly related to changes In cell behaviourism 

 * :'■■.•'-'■: merited Intensive study In their own right. The Immediate 



' -' J."."",' V •.*- ictlon agreed was: J. •-,"'/ ^'v" .:.•''■" 1- '1/ -f 



:t:.'.,j^^:^-^^'-'^'>r'^u:''-^- .-r-' :.*"-. ^v-v-. '-• - - ■• -,. •• . . -u- 



^' -•. J-i'-S"-"-'- W .•' To accept and use hyperplasia as an empirical ■-.".. 



- -■ '. 'r.t>''^,i^i'-{', ■;■/;• - .- grading system of tobacco smoke under the proviso . '<"■ ':'■'■.:. 



■^; J ■/'■'■-•'-:*»; -." '■ that this Interpretation of the results was the ' ^x•^-• 



^ 'r^'-i.'.}-^ •>}''•''!''.''' ■ responsibility of the user, ."ii;: -.;• • f ' .-..■;■.. :■'■ 



:-^ ,;%'<^3Hfv i^-i-'A... / ■ •■-'•.■. ' '-"-ri- i:- ■ '.. ■■■■ . ' . ; 



. ■ _' .-^A . - .(11) To support research Into the meaning and ". 



'<:••''?/ T"v/-.' -' Interpretation at the cellular level of the various .^ 



-".V --.^-j'" "•■'•'.,".".7 short-term tests. ..•' ' "T -^ V . ; ""^ 



•'^ 11.'^^ .Dr. Green stated that hyperplasia tests could be made available to ' ,j 



>.'-:,.'•. V-' members for about $ 1,000 per test. Dr. Griffith and Herr Sottorf ^ 'j 



■ Z. • ' * felt that greater sensitivity might be required beforo adopting this c 

 >-,%.-•■■;■■' test rouflTiely but Dr. Fordyce was of the opinion that attempts at J5 ' " 

 '.-.--..' further refinement would be a waste of time. It was agreed, however, ^ t 

 -■i- ■■•:-". that, with a test of this nature. It would be wise to take samples - 



■ 'J'- '■. with maximum differences in order to establish the trend Jlkcly vj ^^ 



»■ : to be found with commercial samples rather than submit proposed " .;■ 

 •■'■"'"'' and cuaent brands. ;.' " '■- 



S^^2i2^^i^g>^ 



