194 General Discussion 



It has been established that the fatty acids in cholesterol esters 

 are the most highly unsaturated ones in any type of lipid, and fat 

 load as well as cholesterol load on the metabolism will hasten the 

 development of essential fatty acid deficiency in rats. It is therefore 

 probable that the essential fatty acids play a role in the transport 

 of cholesterol. The analytical figures for essential fatty acids just 

 quoted, however, indicate that the solution is not as simple as all that. 



The effect of different types of fat on blood cholesterol must 

 necessarily be established in studies on humans. Most of the funda- 

 mental problems, such as integration of exogenous and endogenous 

 cholesterol in metabolism, transport and eventually, in abnormal 

 tissue, deposition will, according to my judgment, be most profitably 

 studied in animals, and my belief is that most of the fundamentally 

 new results will be obtained by means of animal work. 



This is, in my view, a typical example in reply to your primary 

 question: you need studies in humans, but surely the solution to 

 the fundamental problems will originate from animal experiments. 

 We need the descriptive work in humans before we turn to the pene- 

 trating analytical and biochemical work in animals. 



Verzdr: I was glad that Prof. Tunbridge brought a little optimism 

 into our work on humans again, because listening to all the diffi- 

 culties and all the criticism during these two days one tends to lose 

 the belief that one can work on humans at all. 



We ourselves, in spite of being animal physiologists, thought that 

 our main subject should be man. We started a team which has been 

 working in Basle now for two years, selecting so-called normal men 

 whom we intend to study during the next 30 years. We found a 

 factory which has a fairly continuous working unit, the young men 

 enter it at about 20-22 and spend all their working years there. 

 W T ith the help of Dr. Karl Miescher it was possible to get 50 new 

 persons a year from this factory. The second lot is now being studied. 

 We hope to get up to 200 individuals, each of whom should be studied 

 every second year and the continuous ageing during their life should 

 be worked out. This is rather an optimistic scheme and its success 

 depends on two things : first, that such individuals shall be available 

 and that these 200, or at least half of them, will be there in 30 years 

 time; secondly, that our organization works in such a way that the 

 subjects should not need to lose more than one working morning in 

 the year, which is the maximum which the factory will allow. Also, 

 we must make no measurements which are painful to them, e.g. 

 arterial or venous punctures. Furthermore, if the scheme goes on, 

 some of us who are carrying out this study now will have been replaced 

 by others and the methods, therefore, have been standardized. The 

 subjects come in three at a time to the Medical Polyclinic, where 



