General Discussion 53 



ageing ill an individual in the normal tissue. One can tell it in patho- 

 logical tissue, but in normal tissue, can you come to any rough 

 conclusions as to the age of an individual? 



Cozvdry: I think that can be done with the greatest ease. All you've got 

 to do is to look at the skin on the back of the hand of an individual — ^or 

 you can tell the age of the woman you are going to employ as a secretary 

 by the look of her face. You can tell roughly the age of skeletal muscle 

 by the diameter of the fibres, the amount of elastic tissue and tissue 

 fluid between the fibres. You can tell the old age pigment when you see 

 it in the pigmented tissues of the body. I think there are many rough 

 histological or cytological criteria of age. 



Tunbridge: But you have chosen the two sites on the skin where you 

 can show it, the face and the back of the hand. Why does it not occur on 

 the inner side of the forearm or on the body? I think if you were shown 

 sections of skin from the abdomen. Just the superficial layers, of people 

 aged say ten, fifty and eighty, you would find it rather difficult, with no 

 clue, to know in which order to place them. 



Cowdry: Why don't we find these changes on the ventral surface of 

 the hand? W^ell, one reason is that most of these age changes go with 

 exposure. The dorsal surface is exposed, the face is exposed, the back 

 generally isn't exposed, and the anterior surface of the thigh isn't 

 exposed. You can determine the age by the decrease in the number of 

 sweat glands, b}^ the changes in the hair, by the pigmentation, or the 

 atrophy that you get with some ages: those are the changes that are 

 revealed microscopically. 



Tunbridge: But are they general? They occur in certain sites, but are 

 not mdespread. 



Cowdry: I agree, there is the greatest difference in different parts of the 

 body. Leaving the skin, let us consider the difference in speed of age change 

 in the coronary and radial arteries. The alterations in the radial artery 

 with age are nothing like as conspicuous as those in the coronary artery. 



Shock: Isn't this an issue now of a distinction between what has been 

 called a built-in ageing process and the cumulative changes? Here is a 

 case where you can detect changes with time in tissue exposed to daily 

 trauma over a life-time. But I'd like to point out that in essence you are 

 making the distinction on what isn't there any more, in other words the 

 loss of living cells. I think the question that Dr. iVub raised is, that 

 given the cell that is still in the skin of the eighty-year-old man, is that 

 cell as a unit any different from the cell that is in the skin of the ten- 

 year-old? We don't want to know what, the differences are in the things 

 that have disappeared, we want to know how the things that remain are 

 functioning. Can you detect any differences? 



Cowdry: Pigment is an indication to some extent — the pigment in 

 connective tissues, and nerve cells, for example. 



Albertini: There must be a certain connection between the so-called 

 "elastoid degeneration" of the skin and the carcinoma of the skin in 

 old age. 



Very often degeneration of elastic fibres may be observed in skin 

 with basal cell carcinoma. The degeneration of elastic tissue can only 



